Sunan Abi Dawud 3234
سنن أبي داود#3234SahihNarrated Abu Hurairah:The Messenger of Allah (ﷺ) visited his mother's grave and wept and cause those around him to weep. The Messenger of Allah (ﷺ) then said: I asked my Lord's permission to pray for forgiveness for her, but I was not allowed. I then asked His permission to visit her grave, and I was allowed. So visit graves, for they make one mindful of death
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih Muslim (976)
In-book reference: 21:146