9:29 Fight those who do not believe in Allah or in the Last Day and who do not consider unlawful what Allah and His Messenger have made unlawful and who do not adopt the religion of truth from those who were given the Scripture – [fight] until they give the jizyah willingly while they are humbled.
9:123 O you who have believed, fight those adjacent to you of the disbelievers and let them find in you harshness. And know that Allah is with the righteous.
Sahih Bukhari Book#8 Hadith#387
Narrated Anas bin Malik: Allah’s Apostle said, “I have been ordered to fight the people till they say: ‘None has the right to be worshipped but Allah.’ And if they say so, pray like our prayers, face our Qibla and slaughter as we slaughter, then their blood and property will be sacred to us and we will not interfere with them except legally and their reckoning will be with Allah.”
Jihad means to be involved in fighting in the path of Allah by one’s life, wealth, and speech. (al-Badai us-Sanai)
It is further explained to call the unbelievers towards the true Religion of Islam and to fight against them, if they are unwilling to accept this true Religion. (Fathul Qadeer)
The Muslims are to fight with the Kuffar (disbelievers) to advance Allah’s Religion. (Hashiyatul Adwi/Ash Sharhus Sagir)
The meaning of Jihad in Shari terms is to make utmost effort in fighting in the path of Allah. (Fathul Bari)
Jihad means to fight against the unbelievers. (Matalibe Ulin Nuha)
Imam Al Haleemi in Suab al Iman
Allah clarified that if it weren’t for Allah checking the nonbelievers through the believers and giving the believers authority to protect Islam and break the armies of disbelief, disbelief would have reigned on earth and the true religion would have been eliminated. This proves that the reason for the survival of religion (i.e., Islam) is Jihad and whatever is in this status deserves to be a pillar of Iman.
Imam Shafi’i states
The minimum participation in Jihad is once a year, and more is always better. It is not allowed to have a year pass you by without any fighting except out of necessity like the weakness of Muslims and the great numbers of the enemy, or fear of extermination if you attack them first, or lack of provisions, or similar excuses. Otherwise, if there is no necessity it is not allowed to delay attacking the non-believers for more than a year.
The imam of al Haramain says:
I adopt the opinion of the scholars of usool. They stated that Jihad is a mandatory call and must be established according to the ability until none remains in the world but a Muslim or one who has submitted to Muslims. Thus, Jihad is not limited to once a year. It should be done more frequently if possible. What the scholars of fiqh stated is because usually the time spent in preparations for combat limit the ability to wage war to once a year.
The author of al Mugni from the Hanbali school states
The minimum jihad is once a year, so it is mandatory every year. If there is a need to fight more than once a year, it becomes mandatory on the Muslims to fulfill that need.
Al Qurtubi states in his tafseer
It is mandatory on the Imam to send an army of Muslims to the land of the enemy once every year and the Imam should participate himself in such expeditions. If not, then he should send someone capable whom he trusts, to call them to Islam, keep away their harm, to give victory to the religion of Allah, until they enter Islam or pay jizyah
Al Inayah Sharh al Hidayah (Hanafi)
Jihad is calling towards the true religion and fighting with one’s soul and wealth against those who reject it.
Mawahib al Jaleel fi Sharh Mukhtasar Khalil (Maliki)
Jihad is a Muslim waging war against a non-Muslim who has no peace agreement with Muslims and the fighting is for the sake of the word of Allah to prevail. Jihad is also fighting the non-Muslim who attacks Muslim territory and it is also the Muslims attacking the non-Muslims in their land.
Book of jihad by Ibn Nuhaas
Jihad is a cure for the individual and the society. It cures the individual by delivering him from the sickness of disbelief to the wellbeing of Islam. Disbelieving in Allah is the greatest disease of all and the most destructive on all humanity, while Islam is the complete cure. Jihad cures the society by eliminating the source of corruption and oppression. Leaving the disbeliever unharmed increases the disease and strengthens it and allows the cancer to spread. Therefore Islam cannot flourish and Muslims cannot live in peace unless the disease is cured.
Jihad is not only for defense sake (By Sheikh Ibn Baaz)
Offensive vs Defensive Jihad by Abdullah Azam
Where the Kuffar are not gathering to fight the Muslims. The fighting becomes fard Kifaya with the minimum requirement of appointing believers to guard borders, and the sending of an army at least once a year to terrorize the enemies of Allah. It is a duty Of upon the Imam to assemble and send out an army unit into the land of war once or twice every year. Moreover, it is the responsibility of the Muslim population to assist him, and if he does not send an army he is in sin. And the Ulama have mentioned that this type of jihad is for maintaining the payment of Jizya. The scholars of the principles of religion have also said: “Jihad is Da’wah with a force, and is obligatory to perform with all available capabilities, until there remains only Muslims or people who submit to Islam.”
Definition and ruling of Jihad by Muhammad Masood Azhar
Offensive Jihad is when the Muslims launch an offensive attack. If this attack is on the Kuffar who have previously received the message of Islam, then to call them towards Islam before commencement of the attack is considered preferable. If the message of Islam has not reached them, then the kuffar will be invited towards Islam. If threy reject this true faith, then they will have to pay Jizyah (Kufr Tax). If they refuse to submit to the payment of Jizyah then the Muslims are to fight against them.
It is stated in Fatawa Shami: “It is required of the Imam (leader) of the Muslims to dispatch the army routinely once or twice a year towards the kufr countries. It is also the duty of the Muslim public to assist the Imam in this noble cause. If the Imam does not send an army, then he will be considered sinful.”
The majority of Jihad undertaken at the time of our Prophet Muhammad (salallahu ‘alayhi wasallam) was within the category of offensive Jihad. ”