Sahih Bukhari Volume 3, Book 30, Hadith Number 111.

Narated By Anas : (The people of) Bani Salama intended to shift near the mosque (of the Prophet) but Allah’s Apostle disliked to see Medina vacated and said, “O the people of Bani Salama! Don’t you think that you will be rewarded for your footsteps which you take towards the mosque?” So, they stayed at their old places.