Sahih Muslim
The Book of Games and the Animals which May be Slaughtered and the Aninals that Are to be Eaten (Kitab-us-Said wal-Dhabaih wa ma Yukalu min Al-Hayawan)
Book Number: 021 / Hadith Number: 4784
Ibn 'Umar reported: A person asked Allah's Messenger (may peace be upon him) about the eating of the lizard, whereupon he said. I neither eat it, nor do I prohibit it.