Isaiah 9:6 is the verse that is often interpreted as calling the Messiah, whose birth is being prophesied, "Everlasting Father" which some traditions understand as everlasting God:
"For to us a child is born, to us a son is given; and the government shall be upon his shoulder, and his name shall be called Wonderful Counselor, Mighty God, Everlasting Father, Prince of Peace."
It's important to understand that the interpretation of this verse is complex and varies among different theological traditions.