﴿ وَمَا يُدْرِيكَ لَعَلَّهُۥ يَزَّكَّىٰٓ ﴾

“Yet for all thou didst know, [O Muhammad,] he might perhaps have grown in purity,”

(What could inform thee) O Muhammad (but that he might) i.e. the blind man (grow (in grace)) became righteous through the admonitions of the Qur'an