Tafsir of Nuh 71:27

"Indeed, if You leave them"—meaning, upon the earth, whether all of them or some of them.

"they will mislead Your servants"—away from the path of truth. It may be that what is meant by them are those who believed in him (peace be upon him), and their misleading them refers to turning them back to disbelief through some form of deception. Or, it may refer to those who are born from them who have not yet reached the age of accountability, or those who will be born from those believers and are invited to faith, and their misleading them refers to barring them from faith. In some narrations, it is mentioned that a man among them would bring his son to him (peace be upon him) and say: "Beware of this man, for he is a liar," and that his father had given him the same instruction. Thus, the elder would die, and the younger would grow up upon that [belief]. It is said that it is from this [context] that he (peace be upon him) said:

"and they will beget none but wicked disbelievers"—meaning, those who will eventually commit wickedness and disbelieve. He described them by what they will become due to the firmness of his knowledge regarding that, derived from the experience he gained over nine hundred and fifty years. Similar to this is his (peace be upon him) statement: "If You leave them, they will mislead Your servants." It is also said that he meant those who were naturally disposed toward wickedness and disbelief, and he knew all of that through revelation, as in His (Glorified is He) saying: "None will believe from your people except those who have already believed."

It is reported from Qatadah, Muhammad bin Ka'b, Al-Rabi', and Ibn Zayd that he (peace be upon him) did not supplicate against them until Allah (the Exalted) had brought out every believer from their loins and rendered the wombs of their women barren. Regardless of the case, his saying, "Indeed, You..." and so forth, is an apology for what might be said—that supplicating for [their] total eradication, despite the possibility that there might come from their descendants those who would believe, is not befitting the station of the Prophets (peace be upon them).