Surah Ash-Shu'ara, ayah 33

وَنَزَعَ يَدَهُۥ فَإِذَا هِيَ بَيۡضَآءُ لِلنَّٰظِرِينَ ٣٣

Wanaza'a yadahū fa idhā hiya baydā'u lin-nāzirīn

And he drew out his hand; thereupon it was white for the observers.