It existed before his creation and during his physical life...
It existed before his creation and during his physical life and it has continued to exist after his death and will continue to be popular and effective in future. It was Adam’s practice to offer the Holy Prophet*(Peac Be Up Him and His Household)* as intermediary to Allah for the forgiveness of his lapses. When he chose the Prophet*(Peac Be Up Him and His Household)* as his intermediator, Allah condoned his act of disobedience.
What could be a greater example of the immediate effectiveness of mediation when it is channelized through the Holy Prophet*(Peac Be Up Him and His Household)* ?
Tabarānī, Bayhaqī, Ibn-ul-Mundhir and Suyūtī narrated this tradition through ‘Umar bin al-Khattāb and ‘Alī that the Holy Prophet*(Peac Be Up Him and His Household)* said, “Adam was just about to repent for his act of disobedience that he suddenly recalled in his state of anxiety that he had seen lā ilāha illallāhu Muhammad-ur-rasūlullāh (there is no god but Allah, Muhammad is Allah’s Messenger) inscribed on the Throne at the time of his birth.” It obviously meant that the distinction the Prophet*(Peac Be Up Him and His Household)* possesses is denied to others.
That is the reason his name was inscribed along with Allah’s Own name. At this, he added these words of intermediation to his prayer for divine forgiveness: (O Allah,) I beg Your forgiveness through the mediation of Muhammad (Peac Be Up Him and His Household)* .* The tradition related by Ibn-ul-Mundhir has the following words: O Allah, I beg Your forgiveness through Your beloved and most honoured servant Muhammad and through his distinction You have blessed him with.[1] By the addition of these words of intermediation, the prophet Adam’s repentance was accepted immediately.
Allah said, “In fact, Muhammad is the most beloved of all My creatures. Since you have intermediated your petition through him, I have granted it.
And were it not for Muhammad, I would not have created you.” Tabarānī further adds that Allah said, “He is the Last Prophet among your children.” Imam Hākim has phrased the tradition in these words: Narrated by ‘Umar bin al-Khattāb: Allah’s Messenger (Peac Be Up Him and His Household)* said: When Adam committed the error, he submitted (to Allah): O Lord, I beg You to forgive me through the mediation of Muhammad. Then Allah said: O Adam!