I don’t know of any online commentaries on Isaiah from a Catholic perspective. However, there are several older Protestant commentaries at bible.crosswalk.com/Commentaries/ .
Of course, none of these Protestant commentaries make the obvious connection between Isaiah 22:15-24 and Matthew 16:18-19, Luke 12:41-46, John 21:15-17 and the establishment of the papacy.
It is the night when the Son of God came into the world in Bethlehem, as foretold by the prophets and as we have heard in the first reading: “The Lord himself will give you a sign. Behold, a young woman shall conceive and bear a son, and you shall call his name Emmanuel” (Is 7:14). These words, spoken many centuries ago, were fulfilled on the night when the Son conceived by the Holy Spirit in the womb of the Virgin Mary entered the world. *
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