The Book Pertaining to Repentance and Exhortation to Repentance (Kitab Al-Tauba)
Muslim :: Book 37 : Hadith 6624
Hanzala reported: We were in the company of Allah's Messenger (may peace be upon him) and he delivered to us a sermon and made a mention of Hell-Fire. Then I came to my house and began to laugh with my children and sport with my wife. (Hanzala) further reported: I went out and met Abu Bakr and made a mention of that to him. Thereupon he said: I have done the same as you have mentioned. So we went to see Allah's Messenger (way peace be upon him) and said to him: Allah's Messenger, Hanzala has turned to he a hypocrite. And he (the Holy Prophet) said Show respite. And then I narrated to him the story, and Abu Bakr said: I have done the same as he has done. Thereupon he (the Holy Prophet) said: Hanzala, there is a time for worldly affairs and a time for (worship and devotion), and if your state of mind is always the same as it is at the time of remembrance of Allah, the Angels would shake hands with you and would greet you on the path by saying: As-Salamu-Alaikum.