Islam, as with other Abrahamic religions, views suicide as one of the greatest sins and utterly detrimental to one's spiritual journey. A verse in the Quran instructs;
"And do not kill yourselves, surely God is most Merciful to you."
— Qur'an, Sura 4(An-Nisa), ayat 29 [11]
Most Muslim scholars and clerics consider suicide forbidden and similarly include suicide bombing as being equally forbidden.
However, those who engage in Islamic terrorism, including those who attacked the World Trade Center on September 11, 2001, believe that those who use suicide attacks to kill "infidels" are rewarded with seventy-two virgins in paradise. Islamic spiritualism is not attained without maintenance and forbearance of peace. Bukhari and Muslim, two of the most renowned scholars in Islam, state: "He who believes in God and the Last Day should honour his guest, should not harm his neighbour, should speak good or keep quiet.". This provides an incentive for Muslims to preserve peace in order to attain higher status in the eyes of God. This applies to non-Muslims as well as Muslims as seen in the following quote by Prophet Muhammad: “Beware! Whoever is cruel and hard on a non-Muslim minority, or curtails their rights, or burdens them with more than they can bear, or takes anything from them against their free will; I [Prophet Muhammad] will complain against the person on the Day of Judgment.”
Abu Dawud: "This puts suicide bombing and suicide into proper perspective within Islamic traditions, ultimately denouncing suicide of any form."
The prohibition of suicide has also been recorded in statements of hadith, (sayings of Muhammad). For example:
Narrated Abu Huraira: The Prophet said, "He who commits suicide by throttling shall keep on throttling himself in the Hell Fire (forever) and he who commits suicide by stabbing himself shall keep on stabbing himself in the Hell-Fire."
—Sahih al-Bukhari, 2:23:446
Narrated Abu Huraira: The Prophet said, "Whoever purposely throws himself from a mountain and kills himself, will be in the (Hell) Fire falling down into it and abiding therein perpetually forever; and whoever drinks poison and kills himself with it, he will be carrying his poison in his hand and drinking it in the (Hell) Fire wherein he will abide eternally forever; and whoever kills himself with an iron weapon, will be carrying that weapon in his hand and stabbing his abdomen with it in the (Hell) Fire wherein he will abide eternally forever."
— Sahih al-Bukhari, 7:71:670
Furthermore, Ja'far Al-Sadiq, the sixth Shia Imam, has said the following with regards to suicide:
Abi Walad said, I heard Aba Abd Allah say: “Whoever kills himself, intentionally, he will be in the fire of hell for eternity.”