Allah has never made two hearts in a body, nor does He regard your wives whom you do Biharr’ as your mother, and has not made your adopted son as your son, that is your words uttering with your mouth, and Allah is saying the Truth, and He is guiding to the straight path.
“Allah has never made two hearts in a body” means belief and denial won’t be assembled in one’s heart at a time. It is told in verse 76: 3 that Allah has given a choice to everyone either to be grateful or to be ungrateful. It is told in 64: 2 that Allah has created you, and there is disbeliever among you, and there is believer among you, and Allah is watching whatever you are doing.
‘Dhihar’ means pointing out, comparing, examining, etc. In the ignorant period there existed a custom named ‘Dhihar’ saying to the wife “You are just like my mother to me”, and thus they abstained from having sex with their wives. By revealing this verse Lord Allah banned this evil custom from continuing. See explanation 4: 23; 33: 40. The custom of calling the adopted son suffixing the name of the foster father is also banned through this verse. Without having any proof or evidence from the Lord’s Book, whatever custom is practiced in the label of Islam, is meaningless and hypocritical. See explanation 4: 23; 9: 30; 31: 20.