Thereafter, the verse (7:108) said, وَنَزَعَ يَدَهُ فَإِذَا هِيَ بَيْضَاءُ لِلنَّاظِرِينَ 'And he drew out his hand, and it was white light to the onlookers.'
The Arabic word: نَزع naza` a signifies extracting something from another thing with force. Here this word indicates that the prophet Musa (علیہ السلام) applied some force while drawing out his hand. The verse does not speak of a place from where he drew out his hand. In other verses, however, we find mention of two things. In a verse (27:12) we find the words أَدْخِلْ يَدَكَ فِي جَيْبِكَ 'enter your hand under your robe.' The other verse (20:22) contains the words (وَاضْمُمْ يَدَكَ إِلَىٰ جَنَاحِكَ ) 'put your hand under your arm.' The two phrases indicate that he used to draw out his hand either from under his arm or from under his shirt. Arabic word: بَيْضَاءُ 'bay’ da' means white. The whiteness of hand may also be due to some disease, it is perhaps, why the Holy Qur'an has added the words 'without an evil' in other (28:32, 27:12) verse to eliminate any possible doubt of a disease. We know from a Tradition reported by the Companion ` Abdullah ibn ` Abbas ؓ that this whiteness was not of ordinary kind. It had light that illuminated the whole surrounding. (Qurtubi) The Arabic word 'nazirin' signifying the 'onlookers or viewers' indicates that this light was so surprising for the people that they gathered to see it.
The prophet Musa (علیہ السلام) performed two miracles at this occasion on the demand of the Pharaoh. First, the transformation of his staff into a serpent, second, drawing his hand out from under his arm, emanating light from it. The first was to serve as warning for the unbelievers while the second aimed at inviting them to the truth. It also indicated that the message of the prophet Musa (علیہ السلام) was a light and to follow it would lead people to eternal success.