(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.
Reference: Bulugh al-Maram 561
In-book reference: Book 3, Hadith 29
English translation: Book 3, Hadith 585