“As it is written
I am sending
Ahead of you.
He will prepare
Καθὼς γέγραπται ἐν τῷ Ἡσαΐᾳ τῷ προφήτῃ Ἰδοὺ ἀποστέλλω τὸν ἄγγελόν μου πρὸ προσώπου σου, ὃς κατασκευάσει τὴν ὁδόν σου·
Just as in Matthew, chapter 3:3, Mark began his account about John the Baptist by citing the prophet Isaiah by name (Καθὼς γέγραπται ἐν τῷ Ἡσαΐᾳ τῷ προφήτῃ). Just as Matthew followed Mark, they both introduced John as a fulfilment of a prophecy from the Book of Isaiah. However, Luke, chapter 3:4-6, had a more extended citation from Isaiah. This text here is a composite of texts from Isaiah and Malachi. This specific citation about John is actually from the prophet Malachi, chapter 3:1, not the prophet Isaiah. This same saying about John the Baptist can be found word for word in Luke, chapter 7:27 and Matthew, chapter 11:10. In Malachi, Yahweh was going to send his messenger or angel before him or his face (Ἰδοὺ ἀποστέλλω τὸν ἄγγελόν μου πρὸ προσώπου σου) to prepare the way for him (ὃς κατασκευάσει τὴν ὁδόν σου). Originally, Yahweh would re-enter into his Temple, because the messenger of the delightful covenant had prepared things for him. There is no mention of the Temple here. John was clearly inferior to Jesus, since he was there to prepare the way for Jesus as his messenger, much like an angel of God.