Verse 29

لِّئَلَّا يَعْلَمَ أَهْلُ ٱلْكِتَـٰبِ أَلَّا يَقْدِرُونَ عَلَىٰ شَىْءٍ مِّن فَضْلِ ٱللَّهِ وَأَنَّ ٱلْفَضْلَ بِيَدِ ٱللَّهِ يُؤْتِيهِ مَن يَشَآءُ وَٱللَّهُ ذُو ٱلْفَضْلِ ٱلْعَظِيمِ

This is so that the people of the scripture may know that they have not monopolized anything of God’s grace. That all grace is indeed in God’s hand and He bestows it upon whomever He wills. And God possesses infinite grace.