Sahih Muslim 5848
صحيح مسلم#5848SahihAbu Huraira reported Allah's Messenger (ﷺ) as saying (that he who kills a gecko) with the first stroke there are seventy rewards for him
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 39:199