Why did the Prophet (peace be upon him) not call the Adhan, and are the Ibrahimiyyah Prayer and the Two Testimonies related to that?

It has not been established that the Prophet, peace and blessings be upon him, used a wording other than the known one in the Tashahhud, nor did he say in sending blessings upon himself: "Allahumma salli 'alayya (O Allah, bless me)." As for his Tashahhud in the Adhan, had he called the Adhan, he would have been entitled to say: "Ashhadu anni Rasulullah (I bear witness that I am the Messenger of Allah)" or "Ashhadu anna Muhammadan Rasulullah (I bear witness that Muhammad is the Messenger of Allah)." It has been established that he said in his sermons and on some occasions: "Wa ashhadu anna Muhammadan Rasulullah (And I bear witness that Muhammad is the Messenger of Allah)" and "Ashhadu anni Rasulullah (I bear witness that I am the Messenger of Allah)."