Surah 78. An-Naba, Ayah 36

I.e., not merely in accordance with their good deeds but far in excess of them, in accordance with God's unlimited bounty.

The Recompense is not exactly a Reward in proportion to merit, but is rather a Gift or a Bounty from the Merciful-a Gift most amply sufficient to satisfy all desire on that plane of purity. "A Gift (amply) sufficient" might almost be translated: a liberal and bountiful gift. Cf. the phrase, A 'ta fa ahsaba= he gave generously, or bountifully.