Narrated Sa`d
I heard the Prophet (ﷺ) saying, "Whoever claims to be the son of a person other than his father, and he knows that person is not his father, then Paradise will be forbidden for him." I mentioned that to Abu Bakra, and he said, "My ears heard that and my heart memorized it from Allah's Messenger (ﷺ).
Narrated Abu Huraira
The Prophet (ﷺ) said, "Do not deny your fathers (i.e. claim to be the sons of persons other than your fathers), and whoever denies his father, is charged with disbelief."