Musnad Ahmad 1153:521

'Affan narrated to us, he said: Jarir narrated to us, Nafi' narrated to us, he said: Sa'ibah, the freed slave woman of Al-Fakih ibn Al-Mughirah, narrated to me, she said: I entered upon 'Aishah and saw a spear placed in her house. I said: "O Mother of the Believers, what do you do with this spear?" She said: "This is for these geckos; we kill them with it. For the Messenger of Allah, peace and blessings of Allah be upon him, told us that when Ibrahim, peace and blessings of Allah be upon him, was thrown into the fire, there was no creature on earth that did not extinguish the fire for him, except for the gecko; it used to blow upon it. So the Messenger of Allah, peace and blessings of Allah be upon him, commanded us to kill it."