This can be translated as "Was John's authority to baptize people from heaven or from men?" or "Did God tell John to baptize people, or did people tell him to do it?"
## from heaven ##
“from God.” Jewish people avoided referring to God by his name “Yahweh.” Often they used the word “heaven” to refer to him. (See: [[rc://en/ta/man/translate/figs-metonymy]])