‏الصلاة : Hadeeth No:2121 Abu Marthad al-Ghanawi reported Allaah's Messenger (sallAllaahu alayhi wa sallam) as saying: Do not sit on the graves and do not pray facing towards them....

‏الجنة وصفة نعيمها وأهلها‏ : Hadeeth No:6861 This hadith has been narrated on the authority of Abu Ayyub through some other chains of transmitters (and the words are):" Allaah's Messenger (sallAllaahu alayhi wa sallam) went out after the sun had set and he heard some sound and said: It is the Jews who are being tormented in their graves....