وَمَا كُنتَ بِجَانِبِ ٱلطُّورِ إِذۡ نَادَيۡنَا وَلَٰكِن رَّحۡمَةٗ مِّن رَّبِّكَ لِتُنذِرَ قَوۡمٗا مَّآ أَتَىٰهُم مِّن نَّذِيرٖ مِّن قَبۡلِكَ لَعَلَّهُمۡ يَتَذَكَّرُونَ ٤٦
And you were not at the side of the mount when We called [Moses] but [were sent] as a mercy from your Lord to warn a people to whom no warner had come before you that they might be reminded.
Translation: Saheeh International (English)
Each word's meaning and sound
Neither were you present at the side of mount Sinai when I called out to Moses and revealed whatever I revealed to him, so that you could relate that to the people either. Rather, I sent you as a mercy from your Lord to the people and revealed that incident to you, so that you could warn a nation to whom no Messenger had come prior to yourself, perhaps they would take heed and believe in whatever was brought to them from Allah, may He be glorified.
Al-Mukhtasar in interpreting the Noble Quran