Sa'd bin Abu Waqqas (May Allah be pleased with him) said:
The Prophet ﷺ said, "He who (falsely) attributes his fatherhood to anyone besides his real father, knowing that he is not his father, will be forbidden to enter Jannah."

[Al-Bukhari and Muslim].

عن سعد بن أبي وقاص رضي الله عنه أن النبي ﷺ قال: "من ادعى إلى غير أبيه وهو يعلم أنه غير أبيه، فالجنة عليه حرام" ((متفق عليه)).