“Every valley shall be filled, and every mountain and hill shall be brought low; and the crooked shall be made straight, and the rough ways shall be made smooth;”
Luke 3:5 — Greek Interlinear
Church Fathers on Luke 3:5
The Word came, and the voice followed. For the Word first works inward, then follows the office of the voice, as it is said, And he went into all the country about Jordan.
Jordan is the same as descending, for there descends from God a river of healing water. But what parts would John be traversing but the country lying about Jordan, that the penitent sinner might soon arrive at the flowing stream, humbling himself to receive the baptism of repentance. For it is added, preaching the baptism of repentance for the remission of sins.
It is plain to every reader that John not only preached the baptism of repentance, but to some also he gave it, yet his own baptism he could not give for the remission of sins.