وَمَا كُنتَ بِجَانِبِ الطُّورِ إِذْ نَادَيْنَاAnd you were not at the side of At-Tur when We called.Qatadah said that:وَمَا كُنتَ بِجَانِبِ الطُّورِ إِذْ نَادَيْنَا (And you were not at the side of At-Tur when We did call), refers to Musa, and this -- and Allah knows best -- is like the Ayah:وَمَا كُنتَ بِجَانِبِ الْغَرْبِىِّ إِذْ قَضَيْنَأ إِلَى مُوسَى الاٌّمْرَAnd you were not on the western side (of the Mount), when We made clear to Musa the commandment,Here Allah puts it in a different and more specific way by describing it as a call.This is like the Ayat:وَإِذْ نَادَى رَبُّكَ مُوسَىAnd (remember) when your Lord called Musa. (26:10)إِذْ نَادَاهُ رَبُّهُ بِالْوَادِ الْمُقَدَّسِ طُوًىWhen his Lord called him in the sacred valley of Tuwa. (79:16).وَنَـدَيْنَـهُ مِن جَانِبِ الطُّورِ الاٌّيْمَنِ وَقَرَّبْنَاهُ نَجِيّاًAnd We called him from the right side of At-Tur, and made him draw near to Us for a talk with him. (19:52) وَلَكِن رَّحْمَةً مِّن رَّبِّكَBut (you are sent) as a mercy from your Lord,means, `you were not a witness to any of those things, but Allah has revealed them to you and told you about them as a mercy from Him to you and to His servants, by sending you to them,'لِتُنذِرَ قَوْمًا مَّا أَتَاهُم مِّن نَّذِيرٍ مِّن قَبْلِكَ لَعَلَّهُمْ يَتَذَكَّرُونَto give warning to a people to whom no warner had come before you, in order that they may remember or receive admonition.means, `so that they may be guided by that which you bring from Allah.'