He has not given birth and was not born. (Qur'an, 112:3)
They say, 'Allah has a son.' Glory be to Him! He is the Rich Beyond Need. Everything in the heavens and everything on the earth belongs to Him. Have you authority to say this or are you saying about Allah what you do not know? (Qur'an, 10:68)
It is not fitting for Allah to have a son. Glory be to Him! When He decides on something, He just says to it, 'Be!' and it is. (Qur'an, 19:35)