Al-Baqarah 2:217

Thus the Prophet (s) sent forth the first of his raiding parties under the command of ‘Abd Allāh b. Jahsh. They fought against the idolaters and killed [‘Amr b. ‘Abd Allāh] Ibn al-Hadramī in [the sacred month of] Rajab, thinking that it was the last day of Jumādā II. The disbelievers reviled them for making fighting lawful in a sacred month, and so God revealed the following: They ask you about the sacred, the forbidden, month, and fighting in it (qitālin fīhi, ‘fighting in it’, is an inclusive substitution [for al-shahri l-harāmi, ‘the sacred month’]). Say, to them: ‘Fighting (qitālun is the subject) in it is a grave thing (kabīr, ‘grave’, is the predicate), that is, heinous in terms of sin; but to bar (saddun is the subject), people, from God’s way, His religion, and disbelief in Him, in God, and, to bar from, the Sacred Mosque, that is, Mecca, and to expel its people, the Prophet (s) and the believers, from it — that is graver (the predicate of the [last] subject), [that is] more heinous in terms of sin than fighting in it, in God’s sight; and sedition, your idolatry, is graver than, your, slaying’, in it. They, the disbelievers, will not cease to fight against you, O believers, until, so that, they turn you from your religion, to unbelief, if they are able; and whoever of you turns from his religion, and dies disbelieving — their, good, works have failed, that is, they are invalid, in this world and the Hereafter. Thus they will not count for anything and will not result in any reward. The specification of death as a condition is because if that person were to return to Islam [again], his original deeds would not be invalidated, and he will be rewarded for them, and he would not have to repeat them, [deeds] such as [performing] the Pilgrimage: al-Shāfi‘ī is of this opinion. Those are the inhabitants of the Fire, abiding therein.