It wasnarrated that Abu Hurairah said:
"The Prophet (ﷺ) visitedthegrave of his mother and wept, causing the people around him toweep.Then he said: 'I asked my Lord for permission to seekforgivenessfor her, but He did not give me permission. Then I askedmy Lord forpermission to visit her grave and He gave me permission.So visit thegraves, for they will remind you of death.'"
English reference: Vol. 1, Book 6, Hadith 1572
Arabic reference: Book 6, Hadith 1639