Az-Zukhruf - 43:81

قُلْ إِن كَانَ لِلرَّحْمَنِ وَلَدٌ فَأَنَا أَوَّلُ الْعَابِدِينَ
[43:81]
Say: If the Beneficent Allah has a son, I am the foremost of those who serve.
Say: "If (Allah) Most Gracious had a son, I would be the first to worship."
Say (O Muhammad): If the Beneficent One hath a son, then, I shall be first among the worshippers. (But there is no son).