Anas bin Malik narrated that a man said:
"O Messenger of Allah! Shall I tie it and rely(upon Allah), or leave it loose and rely(upon Allah)?" He said: "Tie it and rely(upon Allah)." (ES)
English reference (ES): Vol. 4, Book 11, Hadith 2517 (ES)
Arabic reference (ES): Book 37, Hadith 2707 (ES)