What is the significance of greetings, and did a meeting occur between God and the Prophet during the Isra and Mi'raj?

The preponderant opinion is that the final Tashahhud (testification of faith) is a pillar of prayer, whereas there is a difference of opinion regarding the middle Tashahhud. It has not been reported that the Messenger of Allah, peace and blessings be upon him, received the salutations (Tahiyyat) from Allah Almighty on the night of the Mi'raj (Ascension). The proof of the importance and obligation of the Tashahhud is what Muslim narrated from Ibn Abbas, who said: "The Messenger of Allah, peace and blessings be upon him, used to teach us the Tashahhud as he would teach us a chapter from the Qur'an. He would say: 'All greetings and blessings, all prayers and good things are for Allah. Peace be upon you, O Prophet, and the mercy of Allah and His blessings. Peace be upon us and upon the righteous servants of Allah. I bear witness that there is no god but Allah, and I bear witness that Muhammad is the Messenger of Allah.'"