مَا زَاغَ ٱلْبَصَرُ وَمَا طَغَىٰ
Maa zaaghal basaru wa maa taghaa
His sight did not waver, nor did it overreach.
Both verbs here are borrowed from elsewhere. Zāgha belongs to hearts that slip off true, the verb of the prayer in 3:8 against a heart swerving after guidance, and ṭaghā to Pharaoh going past every limit and to floodwater breaking its banks at 69:11. The passage vouched for the heart six lines earlier, so the eye is the second faculty put on the record, and the two together certify what was seen.