43:81
قُلْ إِن كَانَ لِلرَّحْمَـٰنِ وَلَدٌ فَأَنَا۠ أَوَّلُ ٱلْعَـٰبِدِينَ
qul in kāna lilrraḥmāni waladun fa-anā awwalu l-ʿābidīna
Say, [O Muḥammad], "If the Most Merciful had a son, then I would be the first of [his] worshippers."
— Saheeh International
Say [Prophet], ‘If the Lord of Mercy [truly] had offspring I would be the first to worship [them], but-
— M. A. S. Abdel Haleem
Say (O Muhammad صلى الله عليه و سلم): "If the Most Gracious (Allâh) had a son (or children as you pretend), then I am the first of Allâh’s worshippers [who deny and refute this claim of yours (and the first to believe in Allâh Alone and testify that He has no children)]." [Tafsir At-Tabarî].
— Muhammad Muhsin Khan & Muhammad Taqi-ud-Din al-Hilali