(1)
'Abdur Rahman bin Abi Laila (RAA) and 'Zaid bin Arqam (RAA) used to recite four Takbirat when praying over the dead, but once he said it five times, so I asked him about it. He said to me, 'The Messenger of Allah (ﷺ) used to do so.' Related by Muslim and the four Imams. (RU)
Reference (RU): Bulugh al-Maram 561 (RU)
In-book reference (RU): Book 3, Hadith 29 (RU)
English translation (RU): Book 3, Hadith 585 (RU)