Kharijahbin Zaid bin Thabit narrated that Yazid bin Thabit, who wasolderthan Zaid, said:
"We went out with the Prophet (ﷺ) and when wereached Al-Baqi', we saw a new grave. He asked about it and theysaid:'(It is) so-and-so (a woman).' He recognized the name andsaid: 'Whydid you not tell me about her?' They said: 'You weretaking a nap andyou were fasting, and we did not like to disturbyou.' He said: 'Donot do that; I do not want to see it happenagain that one of youdies, while I am still among you, and you donot tell me, for myprayer for him is a mercy.' Then he went to thegrave and we lined upin rows behind him, and he said four Takbir(i.e. for the funeralprayer)."
English reference: Vol. 1, Book 6, Hadith 1528
Arabic reference: Book 6, Hadith 1595