إِذْ قَالَ لَهُ رَبُّهُ أَسْلِمْ قَالَ أَسْلَمْتُ لِرَبِّ الْعَالَمِينَ
When his Lord said to him, ‘Submit,’ he said, ‘I submit to the Lord of all the worlds.’
Agha Ali Puya Commentary
Commentary on Quran 2:131
[Pooya/Ali Commentary 2:131] Aslim means to submit. The root of the word is islam (complete submission to Allah). Ibrahim submitted and surrendered to the will of Allah and became a true Muslim in the perfect sense of the word.