Wama kana Allahu liyuAAaththibahum waanta feehim wama kana Allahu muAAaththibahum wahum yastaghfiroon (surah Anfal: 33)

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(8:33) But Allah was not to chastise them while you are in their midst; nor was Allah going to chastise them while they sought His forgiveness.  *27

Wa maa kanal laahu liyu`az zibahum wa anta feehim; wa maa kaanal laahu mu`az zibahum wa hum yastaghfiroon

*27). This is a rejoinder to the challenge implicit in the above-mentioned remark of the unbelievers. In response it was explained why people were spared heavenly scourge during the Makkan period of the Prophet's life. The first reason being that God does not punish a people as long as the Prophet is in their midst, busy inviting them to the truth. Such people are rather granted respite and are not deprived of the opportunity to reform themselves by sending a scourge all too quickly. Second, if there are a good number of people in a land who recognize that they have been negligent and heedless and have been guilty of iniquity, who seek God's forgiveness and strive to reform themselves, there remains no legitimate ground for subjecting them to a heavenly scourge. The time for such a scourge comes when a Prophet who has spared no efforts to reform his people feels that he has exhausted all his efforts, and concludes that his people have no justification to persist in their iniquity, and departs from that land or is banished from it by its people or is murdered by them. A scourge from on high then becomes imminent since the people of that land have proven by their deeds their inability to tolerate any righteous element in their midst.