It was narrated from Sahl bin Sa'd that:
The Messenger of Allah said: "This goodness contains many treasures, and for those there are keys. So glad tidings to the one whom Allah makes a key to good and a lock for evil, and woe to the one whom Allah makes a key to evil and a lock to good." (ID)
English reference (ID): Vol. 1, Book 1, Hadith 238 (ID)
Arabic reference (ID): Book 1, Hadith 244 (ID)