Quran 6:74
The word used in the verse is Ab, which may also mean uncle or grandfather (2:133). It may also mean forefathers in general (7:70, 7:173 etc). Whereas, “walid” only means biological father. Similarly, the word zurriya has been used in Quran to include nephew, sons, grandchildren and descendants in general (6:84-86). Please note that God restricted Abraham from supplicating for his mushrik Ab (60:4), but no such restriction is mentioned when he prays for forgiveness of his parents ( 14:41). It indicates that Azar may have been Abraham’s uncle or grandfather etc, not necessarily his biological father.