Tafsir of Al-A'raf 7:108

And he drew out his hand, and behold! it was white (with radiance) for the beholders. Musa took his hand out of his cloak after he inserted his hand in it and it was shining, not because of leprosy or sickness. Allah said in another Ayah,

وأدخل يدك فى جيبك تخرج بيضاء من غير سوء

And put your hand into your bosom, it will come forth white without hurt. (27:12) Ibn Abbas said, "without hurt', means, `not because of leprosy'. Musa inserted his hand again in his sleeve and it returned back to its normal color.'' Mujahid and several others said similarly