Concise Quran Commentary
The idolaters swear by Allah, with their strongest oaths, that if Muhammad (peace be upon him) brings them one of the signs they asked for, then they will believe. Say to them, O Messenger: I do not have signs so that I may bring them: they are only with Allah, Who sends them down as He wills. And what will inform you, O believers, that if these signs come, as they request, they still will not believe? Instead, they will persist in their denial and stubbornness, because they in fact do not want to be guided.