Say, [O Muhammad], "If the Most Merciful had a son, then I would be the first of [his] worshippers."
The Saheeh International Quran Translation
قُلْ إِن كَانَ لِلرَّحْمَٰنِ وَلَدٌ فَأَنَا۠ أَوَّلُ ٱلْعَٰبِدِينَSay, [O Muhammad], "If the Most Merciful had a son, then I would be the first of [his] worshippers."