The Letter Sad 38:5. Juz 23, page 453.
أَجَعَلَ ٱلْـَٔالِهَةَ إِلَـٰهًا وَٰحِدًا ۖ إِنَّ هَـٰذَا لَشَىْءٌ عُجَابٌ٥
Maketh he the gods One Allah? Lo! that is an astounding thing.
Sad 38:5, translated by Marmaduke Pickthall