Ат-Тавба 9:4

The Prophet testified to the Truth to the fullest extent to his hearers. After the completion of his divine task, those who still did not embrace the Faith, lost their right to live on God’s earth. They had been kept here for the purpose of trial; on completion of the process of preaching and argumentation, the trial was over. Thereafter, why should they have had any lenience shown to them? This is why, after the completion of the work of the prophets, some sort of destructive calamity befell the unbelievers and they were annihilated. This is exactly what happened to the addressees of the Prophet Muhammad. But, it was not any calamity from the sky which descended upon them. The above-mentioned principle of God was implemented, in this case within the framework of a cause and effect system. First of all, by means of the superior Quranic style of expression and the superior character of the Prophet, the call to the Truth was conveyed to them. Then by giving domination to the monotheists over the Makkan polytheists, the process of argument was completed in their case. When all this was done and still they persisted in rejecting the Truth, they were accused of continuous breach of trust and violation of their pledge and an ultimatum was issued to them that they should reform themselves in four months time; otherwise they would be annihilated. All this was settled on the principles of God-fearing (taqwa) and not on the principle of national politics. The polytheists were silenced at the level of arguments; then they would be warned in advance that they would be given a number of months’ respite to reconsider the matter; the door was kept open for them till the last moment, so that those who repented might join those blessed by God; the case of some tribes who had not violated their agreement was kept separate from the case of those who had.