question #1 Sahih Muslim 63a, Book 1, Hadith 125 : What are the consequences of falsely claiming someone other than one’s biological father as one’s own father in Islam?

Both of my ears heard the Messenger of Allah saying this: He who claimed the fatherhood of anyone else besides his real father knowingly (committed a great sin) ;Paradise is forbidden to him. Abu Bakra asserted that he too heard it from the Messenger of Allah (may peace be upon him ).