﴿ لِيَجْزِيَهُمُ ٱللَّهُ أَحْسَنَ مَا عَمِلُوا۟ وَيَزِيدَهُم مِّن فَضْلِهِۦ ۗ وَٱللَّهُ يَرْزُقُ مَن يَشَآءُ بِغَيْرِ حِسَابٍۢ ﴾

“[and who only hope] that God may reward them in accordance with the best that they ever did, and give them, out of His bounty, more [than they deserve]: for, God grants sustenance unto whom He wills, beyond all reckon­ing.”

so that God may reward them for the best of what they did that is reward them the reward for it ahsana means husna and give them more out of His bounty; and God provides whomever He will without any reckoning one says of someone yunfiqu bi-ghayri hisābin to mean that such a person is so generous that it is as though he does not need to reckon what he spends.