Thoth and Re; from “The Nature and Functions of Thoth in Egyptian Theology” (Edward P. Butler)

“Between Thoth and Re there is such a close relationship that Thoth is commonly referred to in later texts as the “heart [i.e., mind] of Re” […] A text from Esna […] states that Thoth came forth from Re’s heart “in a moment of grief”. In very much the same way, humans are said to have come into existence from tears shed by Re (also said of Atum).
While this myth has its basis in the similarity between the words for Tears’ (remi) and for ‘humans’ (romi) in Egyptian, it underscores the fundamental Egyptian idea of a distance between humans and the natural or cosmic order, a distance even painful on some level for the Gods themselves. This distance is made concrete where it is specified that Re (or Atum ) wept because he was separated from his ‘ Eye’ , i.e., his agency or ‘doing. ’ When she returns, he has fashioned a new eye, so he places the original ‘Eye’ upon his forehead, i.e., as the uraeus serpent whose flame is the defense of the cosmic order Re has established. This order involves a painful degree of separation between the natural order and human experience; but the work of healing this rift is immediately taken up by the Gods who occupy the space thus created, Gods such as Thoth, whom Re assists by delegating some of his own power.
One of the primary ways Thoth facilitates the exchanges across the border between the human and divine realms is, of course, in his function as lord of sacred texts. An important passage from the Book o f the Celestial Cow provides Thoth’ s charter, as it were, in this function. When Re is about to withdraw from his role as immanent sovereign of humanity to take his place on the celestial plane, he says to Thoth, “I am here in heaven, in my place… be a scribe here, have power over those who are here… thou shalt be in my place, my deputy”. Re specifically directs Thoth to create writings pertaining to the netherworld, where those who rebelled and were slain now reside. Here we see the divine authorization for the composition o f the very afterlife literature for which Egyptian civilization is so famous. This body of texts serves to reestablish the communication between Re and his most distant subjects which was broken off at the beginning of the myth.“

— Quoted from: “The Nature and Functions of Thoth in Egyptian Theology”, by Edward P Butler