﴿ وَمَا كُنتَ بِجَانِبِ ٱلطُّورِ إِذْ نَادَيْنَا وَلَٰكِن رَّحْمَةًۭ مِّن رَّبِّكَ لِتُنذِرَ قَوْمًۭا مَّآ أَتَىٰهُم مِّن نَّذِيرٍۢ مِّن قَبْلِكَ لَعَلَّهُمْ يَتَذَكَّرُونَ ﴾

“And neither wert thou present on the slope of Mount Sinai when We called out [to Moses]: but [thou, too, art sent] as an act of thy Sustainer’s grace, to warn people to whom no warner has come before thee, so that they might bethink themselves [of Us];”

Please check ayah 28:47 for complete tafsir.