Sahih Bukhari

Narrated Ibn `Abbas:Regarding the Verse: ""And among men is he who worships Allah's as it were on the very edge."" (22.11). A man used to come to Medina and if his wife brought a son and his mares produces offspring, he would say, ""This religion (Islam) is good,"" but if his wife did not give birth to a child and his mares produced no offspring, he would say, ""This religion is bad.""