Muslims claim that God cannot have a son, but the Koran clearly says;

 

We have sent thee inspiration, as We sent it to Noah and the Messengers after him: We sent inspiration to Abraham, Ishmael, Isaac, Jacob and the Tribes, to Jesus, Job, Jonah, Aaron, and Solomon, and to David We gave the Psalms.  Su 4:163  Section 23.

 

and in the second (Jewish) Psalms we read;

 

I will make clear the Lord's decision: he has said to me, 

 

You are my son, this day have I given you being.