In Egypt the Sun could be manifested in many different forms. In Heliopolitan myths (the city of On, where Joseph settled according to the Bible), the Sun was said to rise every morning between two Sycamore Trees. Other myths portrayed the sky goddess Hathor or Nut as a Sycamoretree and as a heavenly sky goddess in the form of a cow, that gave birth every morning to the Sun as a BULL CALF. In this painting, the Sun is shown rising between two Scyamore trees and also as a BULL CALF, which becomes Horus or Ra-Horakhty, another aspect of the Sun. The deceased hopes to be restored to life just as the Sun is reborn to life every morning as a BULL-CALF. Hathor was worshipped in the Sinai at the Egyptian mining camps of Serabit el Khadim and Timna in New Kingdom Times. I have posited that Israel's worship of the Golden Calf in the Sinai may be allusions to Hathor's giving birth to the Sun as a Golden Calf, Hathor being called NUBT, "The Golden One."
(p.332, New Kingdom period Tomb of Sennedjem at Deir el Medina, Thebes. Kent R. Weeks et al. La Valle Dei Re, Le Tombe E I Funerari Di Tebe Ovest. White Star. Torino, Italy. 2001. ISBN 88-8095-667-1)
Budge notes the birth of the Sun as a Calf-
"The Sycamore of Nut was situated at Heliopolis and is often mentioned in mythological texts. According to the Book of the Dead (cix.4) there were two turquoise-colored sycamores at Heliopolis, and the sun-god passed out between them each morning when he began his journey across the sky..." (p.107, Vol.2,. E.A. Wallis Budge. The Gods of the Egyptians. New York. Dover Publications.  reprint 1969)
"Another view reprsented the sky in form of gigantic cow, her body forming the sky...This cow gave birth to the sun, which was then likened to a calf, and the deceased when re-born in the sky was compared to a suckling calf." (p.132-133, "The Abode of the Blessed." E. A. Wallis Budge. The Book of the Dead. New York. Bell Publishing Company.  reprint 1960)