The Quran lays the groundwork for understanding jihad, presenting it as an all-encompassing struggle. The opening introduction correctly highlights verses that emphasize both a general striving and the more specific act of fighting. For instance, the verse “Allah loves those who fight in His cause in a row as though they are a single structure joined firmly” speaks to the communal strength and unity required in the external dimensions of jihad. Similarly, the command to “strive in the cause of Allah with your wealth and your lives” underscores the commitment of resources—both material and personal—that jihad demands. This concept of striving with "wealth and lives" is echoed in numerous hadith, such as Abu Huraira's narration where he states, “By Him in Whose Hands my soul is but for Jihad (i.e. holy battles), Hajj, and my duty to serve my mother, I would have loved to die as a slave” Bukhari 49:31. This illustrates the high esteem in which jihad is held as a form of devotion.

Crucially, the Quran also provides context for the more challenging aspects of jihad, particularly the command to “fight them until there is no more affliction and the worship is for Allah (Alone)”. Ibn 'Umar's interpretation of this verse, as narrated by Nafi`, is vital. He explains that this command was fulfilled during the Prophet's lifetime when Islam had few followers and people were persecuted for their religion. Once Muslims gained strength and "there was no more affliction or oppressions," the need for such fighting diminished (Bukhari 0:0, 65:40). This interpretation demonstrates that the Quranic injunctions related to fighting are context-dependent, aimed at removing oppression and establishing religious freedom, rather than perpetual aggression. The promise that “those who strive for Us – We will surely guide them to Our ways” further universalizes the concept, implying divine assistance for all forms of righteous exertion, not just military engagement.

The Sunnah, through the teachings and practices of the Prophet Muhammad (peace be upon him), clarifies and elaborates on the Quranic principles of jihad, often prioritizing internal and social dimensions over warfare. When asked about the best deed, the Prophet consistently listed acts of faith and devotion before jihad. Abu Huraira narrates that the Prophet (peace be upon him) identified “To believe in Allah and His Apostle (Muhammad)” as the best deed, followed by “To participate in Jihad (religious fighting) in Allah's Cause”, and then “To perform Hajj” (Bukhari 2:19, 25:7; Muslim 1:155). Similarly, Abdullah bin Masud relates that the Prophet (peace be upon him) considered “To offer the prayers at their early stated fixed times” as dearest to Allah, followed by “To be good and dutiful to your parents”, and then “To participate in Jihad in Allah's Cause” (Bukhari 56:1, 9:6, 97:159; Muslim 1:158, 1:159, 1:160). These narrations underscore that foundational acts of worship and familial duties take precedence, positioning jihad within a broader framework of righteous living.

A particularly illuminating aspect of prophetic guidance concerns exemptions and alternative forms of jihad. For women, the Prophet (peace be upon him) declared “The best Jihad (for women) is Hajj Mabrur” (Bukhari 25:8, 56:3, 56:41, 56:91, 56:92). Aisha's inquiries about participating in holy battles were met with this clear directive, indicating that for women, the arduous spiritual journey of Hajj is considered equivalent to the physical struggle of men in battle. Furthermore, for young men whose parents are alive, the Prophet (peace be upon him) re-directed their desire for physical jihad towards familial duty, instructing them to "“Then exert yourself in their service”" (Bukhari 56:213, 78:3). This highlights the importance of upholding family responsibilities as a form of jihad, demonstrating that the concept is flexible and adaptable to individual circumstances.

The cessation of "Hijra" (migration) from Mecca after its conquest is another significant prophetic ruling. The Prophet (peace be upon him) declared, “There is no more emigration (from Mecca) but Jihad and intentions, and whenever you are called for Jihad, you should go immediately” (Bukhari 28:14, 56:2, 56:282, 56:41, 58:30; Muslim 15:506, 33:125, 33:127). This signified a shift from physical relocation for the sake of faith to a continuous internal struggle (intentions) and, when necessary, external defense. The emphasis on "good intentions" reinforces the spiritual core of all forms of jihad.

Classical tafsir and hadith commentaries further elaborate on the context and purpose of jihad, particularly its defensive and ethical dimensions. The hadith narrated by Hudhaifa, which connects the verse “And spend (of your wealth) in the Cause of Allah and do not throw yourselves in destruction” to spending in Allah's Cause (i.e. Jihad) Bukhari 65:41, suggests that failure to spend on defense or to engage in necessary striving could lead to destruction. This implies a responsibility to be prepared and resourced for the protection of the community.

The Prophet's definition of fighting in Allah's Cause is also crucial: “He who fights so that Allah's Word (i.e. Islam) should be superior, fights for Allah's Cause” Bukhari 57:35. This excludes fighting for personal gain, fame, or tribal pride, establishing a pure, intention-based criterion for legitimate external jihad. The rewards promised for those who strive in Allah's Cause—such as being admitted to Paradise if martyred or returning with reward and booty (Bukhari 57:32, 97:83, 97:89; Muslim 33:155, 33:157)—are contingent on this pure intention and dedication. The profound imagery of a martyr's wound bleeding on the Day of Judgment, with its color like blood but its smell like musk (Muslim 33:155, 33:158, 33:159), signifies the immense spiritual value and purity associated with sacrificing one's life for Allah's sake.

The Prophet's personal longing to be martyred multiple times underscores the spiritual elevation of such a sacrifice: “I wish I could fight in Allah's Cause and be martyred and come to life again to be martyred and come to life once more” (Bukhari 56:181; Muslim 33:160). This profound desire reveals a deep spiritual aspiration rather than a mere call to violence. The blessings associated with horses kept for jihad (Bukhari 56:68, 56:76, 61:149; Muslim 33:143) further highlight the comprehensive nature of participation, where even supporting elements contribute to the spiritual merit.

Fiqh rulings provide the practical framework for the application of jihad, distinguishing between individual and collective obligations and outlining ethical conduct.

Categorization of Obligation: The Hanafi and Maliki schools agree that jihad is generally a collective obligation (fard kifayah). This means that “if a group of people undertakes it, it falls away from the rest” (Hanafi, hidaya: vol 02 p134; Maliki, risala: vol 01 p082). However, in specific circumstances, it can become an individual obligation (fard ayn), such as “if an enemy attacks a country, it becomes obligatory (wajib) upon all people to defend it” (Hanafi, hidaya: vol 02 p134). This distinction is critical, showing that not every individual is perpetually obligated to engage in physical combat.

Exemptions and Permissions: Fiqh echoes the prophetic tradition regarding exemptions. The Hanafi school explicitly states that jihad is “not obligatory upon a child” and “nor is it obligatory upon a slave or a woman” hidaya: vol 02 p134. It also exempts “a blind person, a disabled person, or a person with a severed limb” hidaya: vol 02 p134. However, in cases of general mobilization, these exemptions can be overridden for those capable, with a woman being permitted to go out “without her husband's permission” and a slave “without his master's permission” (Hanafi, hidaya: vol 02 p134). This reflects the severity of the threat that would necessitate such widespread participation.

Pre-Combat Ethics: The Hanafi school emphasizes the principle of invitation before combat: “It is not permissible to fight those who have not received the call to Islam unless they are invited first” hidaya: vol 02 p135. If an invitation has already been extended, it is still “recommended to invite those who have already received the call (to Islam), as an exaggeration in warning, but it is not obligatory” (Hanafi, hidaya: vol 02 p135). This reinforces the Quranic emphasis on guidance and peaceful resolution as the primary objective. Only if they refuse the call to Islam is one to "seek Allah's help against them and fight them" (Hanafi, hidaya: vol 02 p135).

Conduct During Combat and Spoils of War: Strict rules govern combat and the distribution of spoils (ghanima). The Hanafi school outlines the division of spoils, stating that the Imam “divides the spoils of war and takes out one-fifth of it” hidaya: vol 02 p145, with the remaining four-fifths distributed among the warriors hidaya: vol 02 p145. Cavalrymen receive more shares than infantrymen; for instance, according to Abu Hanifa, a cavalryman gets two shares and an infantryman one, while Imam Shafi'i's view is three shares for a cavalryman (Hanafi, hidaya: vol 02 p145). The Hadith about the Prophet (peace be upon him) not allowing `Umar to buy back a horse he had given in charity for jihad Bukhari 55:38 underscores the sanctity of charitable giving for this cause. The Hanafi school also specifies that it is “not permissible for them to sell any of that (spoils before division) nor to acquire it as property” hidaya: vol 02 p143.

Protection of Non-Combatants: An important ethical consideration in warfare is the protection of non-combatants. The Prophet (peace be upon him) "did not kill the children of the enemy" (Muslim 32:166, 32:168), setting a clear precedent against targeting innocents. The Hanafi school allows for throwing projectiles even if there are Muslim captives or merchants among the enemy, stating "there is no harm" hidaya: vol 02 p135, and similarly, if "they shield themselves with Muslim children or captives, they should not stop throwing (projectiles) at them" hidaya: vol 02 p135. This seemingly harsh ruling is typically understood in contexts where military necessity is paramount, and the intent is not to harm Muslims but to overcome a threat, with the harm to Muslims being an unintended consequence of a legitimate military action.

The concept of jihad is deeply intertwined with spiritual rewards and a heightened sense of devotion. The Hadith frequently extols the virtues of jihad, presenting it as a path to immense blessings. The Prophet (peace be upon him) described the "journey undertaken by a person in the morning (for Jihad) in the way of Allah (will merit a reward) better than the world and all that is in it" (Muslim 33:170, 33:171, 33:172, 33:173, 33:169). This hyperbolic praise emphasizes the extraordinary spiritual value of such exertion.

The Prophet's assurance that “Allah guarantees him who strives in His Cause... that He will admit him into Paradise (if martyred) or bring him back to his dwelling place, whence he has come out, with what he gains of reward and booty” (Bukhari 57:32; Muslim 33:155, 33:157) highlights the divine promise for those who commit to jihad with sincerity. The concept of "God laughs at the two men both of whom will enter Paradise (though) one of them kills the other" (Muslim 33:188, 33:190) illustrates the boundless mercy of Allah, where a killer, if guided to Islam and then martyred, can attain the same ultimate reward as his victim. This emphasizes conversion and martyrdom as powerful avenues to divine forgiveness.

Furthermore, participation in jihad extends beyond direct combatants. “Anybody who equips a warrior (going to fight) in the way of Allah (is like one who actually) fights. And anybody who looks well after his family in his absence (is also like one who actually) fights” (Muslim 33:198, 33:199). This broadens the scope of meritorious action, including those who provide logistical support or care for the families of fighters, reinforcing the communal nature of jihad. The warning against betraying the trust of a Mujahid's family Muslim 33:203 further highlights the collective responsibility and sanctity surrounding this endeavor.

In summation, jihad is a multifaceted and profound concept within Islam, rooted in Quranic commands and extensively elaborated upon in the Sunnah and classical jurisprudence. It mandates a continuous spiritual struggle against inner vices, social injustice, and, under strict ethical guidelines, external aggression. The Prophet's teachings prioritize internal faith, familial duties, and fundamental acts of worship, while also delineating the conditions and rewards for physical jihad. Fiqh traditions further provide practical guidelines, emphasizing collective responsibility, ethical conduct in warfare, and the protection of non-combatants. Ultimately, jihad represents a believer's holistic commitment to God, encompassing purification of self, promotion of good, and defense of truth, all aimed at attaining divine pleasure and reward.