Ahmad transmitted on the authority of `Ali (RA): “The earth (dust) has been made for me as a means for purification.”
Bulugh al-Maram

Narrated Abu Hurayrah (RA): The Prophet (peace be upon him) said: He who is asked something he knows and conceals it will have a bridle of fire put on him on the Day of Resurrection.
Sunan Abi Dawud, Book 26, Hadith 18

Narrated `Abdullah bin `Umar (RA): Allah’s Messenger (peace be upon him) said, “Not to wish to be the like except of two men. A man whom Allah has given the knowledge of the Book and he recites it during the hours of the night, and a man whom Allah has given wealth, and he...

Narrated `Abdullah (RA): I used to greet the Prophet (peace be upon him) while he was in prayer and he would return my greeting, but when we returned (from Ethiopia) I greeted the Prophet (while he was praying) but he did not return the greeting, and (after finishing the prayer) he said...

Narrated Um Salama (RA): One night the Prophet (peace be upon him) got up and said, “Subhan Allah! How many afflictions Allah has revealed tonight and how many treasures have been sent down (disclosed). Go and wake the sleeping lady occupants of these dwellings up (for prayers)...