Al-Ahzab · 33:5

5. Attribute those you claim to be your sons towards their real fathers, because attributing them towards them is justice in the eyes of Allah. But if you do not know their fathers to whom you can attribute them, then they are your brothers in religion and the sons of your uncles, so call them by: “O brother” or “O cousin”. And there is no sin on you if one of you makes a mistake and attributes a claimed son towards his claimant, but you will be sinful if you intentionally say that. And Allah is Forgiving to those of His servants who repent, Merciful to them as He did not punish them due to mistakes.