Sahih Muslim Book 32, Hadith Number 6344.

Chapter : The merit of removing of anything troublesome from the path.

Abu Barza reported that he said to Allah’s Messenger (may peace be upon him): Allah’s Messenger, I do not know whether I would survive after you, so confer upon me something by which Allah should benefit me. Thereupon Allah’s Messenger (may peace be upon him) said: Do this and that and remove the troublesome things from the paths.