Surah An-Naml 27:12

وَأَدْخِلْ يَدَكَ فِى جَيْبِكَ تَخْرُجْ بَيْضَآءَ مِنْ غَيْرِ سُوٓءٍ ۖ فِى تِسْعِ ءَايَـٰتٍ إِلَىٰ فِرْعَوْنَ وَقَوْمِهِۦٓ ۚ إِنَّهُمْ كَانُوا۟ قَوْمًا فَـٰسِقِينَ

And put your hand into the opening of your garment [at the breast]; it will come out white without disease. [These are] among the nine signs [you will take] to Pharaoh and his people. Indeed, they have been a people defiantly disobedient."

Translation: Saheeh International

Tafsir

And insert your hand into your bosom into the collar of your shirt and it will emerge not in its usual skin colour but white without any blemish any vestige of leprosy with a glare that dazzles the eyes as one sign among nine signs with which you shall be sent as God’s messenger to Pharaoh and his folk; …

Excerpt from Tafsir al-Jalalayn, commentary on 27:12, via Quran.com. The reader has the full commentary and 9 more tafsirs.