Mu'adh b. Jabal said that the Prophet used to like to pray in al-hitan*. One of its transmitters says that it means gardens.
* I have given the Arabic word because it is explained in the text. Why it should need to be explained is not clear.
Tirmidhi transmitted it and said, “This is a gharib tradition which we know only among the traditions of al-Hasan b. Abu Ja'far whom Yahya b. Sa'id and others have declared to be weak.”
‘Ata’ b. Yasar reported God’s Messenger as saying, “O God, do not let my grave become an idol which is worshipped. God’s anger is severe against people who take the graves of their prophets as mosques.”
Anas b. Malik reported God’s Messenger as saying, “A man’s prayer in his house is equivalent to a single observance of prayer, his prayer in a tribal mosque is equivalent to twenty-five, his prayer in a mosque in which the Friday prayer is observed is equivalent to five hundred, his prayer in the Aqsa mosque is equivalent to fifty thousand, his prayer in my mosque is equivalent to fifty thousand, and his prayer in the sacred mosque (the Ka’ba) is equivalent to a hundred thousand.”
‘Abdallah b. ‘Amr b. al-‘As said that God’s Messenger used to say on entering the mosque, “I seek refuge in God the mighty, in His noble being, and in His power which is from everlasting from the accursed devil.” He said that when the devil heard that he said, “He is protected from me for the rest of the day.”