It is narrated from Sayyiduna Sa’d bin Abi Waqqas (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) ordered the killing of the gecko and called it “fawaysiq” (i.e., a small evildoer).
Sayyiduna Abu Hurairah (may Allah be pleased with him) reports that the Messenger of Allah (peace and blessings be upon him) said: Whoever kills a gecko with the first strike, he will have such-and-such reward; whoever kills it with the second strike, he will have such-and-such reward, but less than the first; and whoever kills it with the third strike, he will have such-and-such reward, but less than the second. In another narration, the Noble Prophet (peace and blessings be upon him) said: Whoever kills a gecko with the first strike, one hundred good deeds will be written for him; whoever kills it with the second strike, he will have less than that; and whoever kills it with the third strike, he will have less than that.