Announcing the Arrival of God

Matthew, in his recounting of the beginning of Jesus' ministry, briefly mentions John the Baptist. In doing so, he quotes from Isaiah 40:3, reporting in 3:3:

A voice of one calling in the desert,
'Prepare the way for the Lord,
make straight paths for him.'

However, looking directly at Isaiah 40:3, we find this:

A voice of one calling:
"In the desert prepare
the way for YHWH;
make straight in the wilderness
a highway for our God.

Matthew was, in essence, telling his readers that John was the forerunner of not merely the "Son" of God, but of God himself, of YHWH on Earth.