Hazrat Abu Usman narrates that a man bought a garden in Madinah and gained as much benefit from it as from a date-palm tree. Upon this, the Prophet (peace and blessings be upon him) said: Shall I tell you of something better than this? A person who performs ablution well, then offers two rak'ahs in a cave or on the top of a mountain, the benefit of this is greater than that person's.