Sheba 34:21. Juz 22, page 430.
وَمَا كَانَ لَهُۥ عَلَيْهِم مِّن سُلْطَـٰنٍ إِلَّا لِنَعْلَمَ مَن يُؤْمِنُ بِٱلْـَٔاخِرَةِ مِمَّنْ هُوَ مِنْهَا فِى شَكٍّ ۗ وَرَبُّكَ عَلَىٰ كُلِّ شَىْءٍ حَفِيظٌ٢١And he had no warrant whatsoever against them, save that We would know him who believeth in the Hereafter from him who is in doubt thereof; and thy Lord (O Muhammad) taketh note of all things.
Saba 34:21, translated by Marmaduke Pickthall