This is a rather basic commentary compiled by Fr. Leo Haydock in the 19th century. Text in red are my additions. I hope to add a few more things to the post latter.
Isa 49:1 Give ear, ye islands, and hearken, ye people from afar. The Lord hath called me from the womb, from the bowels of my mother he hath been mindful of my name.
Give ear, ye islnads, & c. This fresh discourse continues to Isa 54:9., relating to the Messias, who is introduced speaking to all the world, Acts 13:47., and 2 Corinthians 6:2. Some apply a part to Cyrus, Isaias, or John the Baptist, as to his figures. (Calmet) — The prophet has foretold the conversion of the Gentiles, as he now does, like an evangelist. (St. Jerome) — Many Jews will embrace the gospel at the end of time. (Worthington). The text is used as the first reading for the Nativity of St John the Baptist. It is not considered a prophecy regarding the Baptist (historically it’s been applied to Christ). The text contains elements reminiscent of other prophetic call narratives, most notably, the call of Jeremiah. Parts of the text easily lend themselves to a broader application, evidenced by the fact that St Paul and St Barnabas apply the text of Isaiah 49:6 to themselves in acts 13:46-47. The liturgy applies the text to the Baptist in an accommodated sense.
From the bowels (womb) of my mother he hath been mindful of my name. The Angel Gabriel told Zachariah the following concerning his son John: But the angel said to him: Fear not, Zachary, for thy prayer is heard: Thy wife Elizabeth shall bear thee a son. And thou shalt call his name John. And thou shalt have joy and gladness: and many shall rejoice in his nativity (birth). For he shall be great before the Lord and shall drink no wine nor strong drink: and he shall be filled with the Holy Ghost, even from his mother’s womb (Luke 1:13-15). See also Jeremiah 1:5, Gal 1:15-17.
Isa 49:2 And he hath made my mouth like a sharp sword: in the shadow of his hand he hath protected me, and hath made me as a chosen arrow: in his quiver he hath hidden me.
He hath made my mouth like a sharp sword. Sword, penetrating the very soul, (Hebrews 4:12.) and slaying the wicked, Rev 1:16., and 2 Thessalonians 2:8. Without Christ, his ministers can apply this sword to little purpose. Cyrus cut asunder the bonds of the captives by his decree. (Calmet) — Grotius improperly explains all of Isaias. (Houbigant).
The mouth is the prophet’s weapon (Isaiah 6:7; Jeremiah 1:9).
In the shadow of his hand he hath protected me, and hath made me as a chosen arrow: in his quiver he hath hidden me. The divine protection need not refer to the preservation of life, rather, it can refer to the the accomplishment of the mission, even if that mission is to end in martyrdom: But I say to you, that Elias (Elijah) is already come, and they knew him not, But have done unto him whatsoever they had a mind. So also the Son of man shall suffer from them. Then the disciples understood, that he had spoken to them of John the Baptist (Matt 17:12-13).
Isa 49:3 And he said to me: Thou art my servant Israel, for in thee will I glory.
In thee will I glory. In the Church, God is adored in spirit and truth. Isaias is ordered thus to address the Israelites.
Isa 49:4 And I said: I have laboured in vain, I have spent my strength without cause and in vain: therefore my judgment is with the Lord, and my work with my God.
He will reward the labours of his ministers, though the people be obstinate. The prophets and our Saviour frequently complain, Isaias 65:2., and Mark 9:18.
Isa 49:5 And now saith the Lord, that formed me from the womb to be his servant, that I may bring back Jacob unto him, and Israel will not be gathered together: and I am glorified in the eyes of the Lord, and my God is made my strength.
And Israel will not be gathered. Hebrew, Septuagint, &c., “to be gathered.” (Haydock) — The original text, independent of the Masorets, may have the sense of the Vulgate. Yet there are other proofs of the synagogue’s rejection. (Calmet) — Protestants, “though Israel be not gathered, yet,” &c. Marginal note, or “that Israel may be gathered, and I may,” &c. (Haydock)
Isa 49:6 And he said: It is a small thing that thou shouldst be my servant to raise up the tribes of Jacob, and to convert the dregs of Israel. Behold, I have given thee to be the light of the Gentiles, that thou mayst be my salvation even to the farthest part of the earth.
St. Paul, explains this of Christ, (Acts 13) who said, Go teach all nations, Matthew 28. Isaias was one of his first preachers.