God Nabu and Mercury
In Sumer they called Mercury “the bouncing” and it is because of the variable length of his heliacal appearances and disappearances.
Nabu is the son of Marduk-Jupiter. There is a version that Mercury was “recognized” a planet around the second century BC and this associates most likely with the coming to power of Marduk in Babylon. Then they associate Mercury with the coronation of the prince and so is his connection with Jupiter-Marduk, his father. They called Mercury and “the planet of Jupiter”, because of the connection between them. This is due to celestial observations and mythological roots.
Nabu, Mercury is the god of writing and has the tablets of fate of all.
Then they knew that the behavior of Mercury is the most irregular and “wild” in comparison to the other six planets. This was the result of observations of the sky with the naked eye. He used to become “black”, meaning- invisible in the rays of the sun. Similar name had Saturn again due to his invisible heliacally phase and character of a malefic planet.