The Letter Sad 38:17. Juz 23, page 454.
ٱصْبِرْ عَلَىٰ مَا يَقُولُونَ وَٱذْكُرْ عَبْدَنَا دَاوُۥدَ ذَا ٱلْأَيْدِ ۖ إِنَّهُۥٓ أَوَّابٌ١٧Bear with what they say, and remember Our bondman David, lord of might, Lo! he was ever turning in repentance (toward Allah).
Sad 38:17, translated by Marmaduke Pickthall