Surah Ali 'Imran 3:20

فَإِنْ حَآجُّوكَ فَقُلْ أَسْلَمْتُ وَجْهِىَ لِلَّهِ وَمَنِ ٱتَّبَعَنِ ۗ وَقُل لِّلَّذِينَ أُوتُوا۟ ٱلْكِتَـٰبَ وَٱلْأُمِّيِّـۧنَ ءَأَسْلَمْتُمْ ۚ فَإِنْ أَسْلَمُوا۟ فَقَدِ ٱهْتَدَوا۟ ۖ وَّإِن تَوَلَّوْا۟ فَإِنَّمَا عَلَيْكَ ٱلْبَلَـٰغُ ۗ وَٱللَّهُ بَصِيرٌۢ بِٱلْعِبَادِ

So if they argue with you, say, "I have submitted myself to Allāh [in Islām], and [so have] those who follow me." And say to those who were given the Scripture and [to] the unlearned, "Have you submitted yourselves?" And if they submit [in Islām], they are rightly guided; but if they turn away - then upon you is only the [duty of] notification. And Allāh is Seeing of [His] servants.

Translation: Saheeh International

Tafsir

So if they the disbelievers dispute with you O Muhammad (s) concerning religion say to them ‘I have surrendered my countenance to God that is to say I have submitted to Him I and whoever follows me’ wajh ‘countenance’ is chosen here because of its noble character for the other parts of the body will just as soon …

Excerpt from Tafsir al-Jalalayn, commentary on 3:20, via Quran.com. The reader has the full commentary and 9 more tafsirs.