Jerome

. Will not Lebanon soon become a fruitful field, and the fruitful field be regarded as a forest? Let the Jews and friends of simple history answer, those who seek fruit not on the tree, but only leaves and the shadow of words, which quickly wither and perish. How is it that in the coming of the Lord Savior (because from the time of Isaiah until the incarnation of the flesh, for the comparison of eternity, it is a short and small span of time) the mountain of Lebanon turned towards Phoenicia and moved to Mount Carmel? …

Commentary on Isaiah ↗

Bede

Note that [Paul] taught Greeks in Jerusalem, and Jews in Damascus which is a Gentile city, even though this should signify that Gentiles were to be included in the city of God and Jews were to fall into the faithlessness of the Gentiles, in accordance with what Isaiah said, "Lebanon shall be changed into Carmel, and Carmel shall be regarded as a wasteland."

Commentary on Acts 9 ↗

Thomas Aquinas

663. Is it not yet a very little while? Here he foretells the conversion of the gentiles, and concerning this, he does three things. First, he foretells their conversion to grace: Libanus, a gentile people, for the mountain was in the land of the gentiles; into Carmel, into grace, which the Jews had through circumcision, because Carmel means "knowledge of circumcision"; as a forest, that is, as barrenness, which the gentiles were in before, below (Isa 32:15) has the same thing. 666. …

Commentary on Isaiah ↗