Musannaf Ibn Abi Shayba 3:3329

Yazid ibn Harun narrated to us, from al-Mas'udi (Mas'ar), from Ma'bad ibn Khalid, from Kardus, who said: Sa'id ibn al-'As arrived in Dhu al-Hijjah, so he sent for 'Abdullah, Hudhayfah, Abu Mas'ud al-Ansari, and Abu Musa al-Ash'ari. He asked them about the *takbir* (in the Eid prayer), so they referred their matter to 'Abdullah. 'Abdullah said: "He stands and says *takbir*, then says *takbir*, then says *takbir*, then recites. Then he says *takbir* and bows. Then he stands and recites, then says *takbir*, then says *takbir*, then says *takbir*, then says the fourth *takbir*, then bows."