Ibn Hajar, the author of Fath l-Bari Sharh Sahih Al-Bukhari said:

“With regard to the format of the takbeer, the most saheeh that has been narrated concerning it is that which was narrated by ‘Abd al-Razzaaq with a saheeh isnaad from Salmaan who said: “Proclaim Allah’s greatness: Allahu akbar, Allahu akbar, Allahu akbaru kabeeran.”

Fath al-Baari, 2/462 … More TAKBEERAT OF EID EXPLAINED – MOST AUTHENTIC TAKBEERAT – THE WAY SAHABA SAID THE TAKBEER ON EID – FIQH OF TAKBEER