"Say, what thing is greatest in testimony?" Al-Kalbi said:
The polytheists among the people of Mecca said to the Prophet: Who knows that you are the Messenger of Allah so that they may bear witness for you? So Allah revealed: "Say, Allah is witness between me and you." He is the witness that I am His Messenger.
"And this Quran was revealed to me that I may warn you thereby and whomever it reaches," meaning: whoever the Quran reaches.
﴿قُلْ أَيُّ شَيْءٍ أَكْبَرُ شَهَادَةً﴾ قَالَ الْكَلْبِيُّ:
قَالَ الْمُشْرِكُونَ مِنْ أَهْلِ مَكَّةَ لِلنَّبِيِّ: مَنْ يَعْلَمُ أَنَّكَ رَسُولُ اللَّهِ فَيَشْهَدُ لَكَ؟ فَأَنْزَلَ اللَّهُ: ﴿قُلْ أَيُّ شَيْءٍ أَكْبَرُ شَهَادَةً قُلِ اللَّهُ شهيدٌ بيني وَبَيْنكُم﴾ فَهُوَ شَهِيدٌ أَنِّي رَسُولُهُ.
﴿وَأُوحِيَ إِلَيّ هَذَا الْقُرْآن لأنذركم بِهِ وَمن بلغ﴾ أَيْ: مَنْ بَلَغَهُ الْقُرْآنُ.
