Surah Al-Baqarah, ayah 131

2:131

إِذۡ قَالَ لَهُۥ رَبُّهُۥٓ أَسۡلِمۡۖ قَالَ أَسۡلَمۡتُ لِرَبِّ ٱلۡعَٰلَمِينَ ١٣١

Idh qāla lahū rabbuhū aslim qāla aslamtu lirabbil-'ālamīn

When his Lord said to him, "Submit," he said, "I have submitted [in Islām]45 to the Lord of the worlds."

Footnotes

45 The meaning of the word "Islām" is "submission to the will of Allāh." This is the way of life ordained by Allāh and taught by all of the prophets from Adam to Muḥammad (ﷺ). A Muslim is one who submits himself to Allāh.