Isaiah 6:8 (BSB)

Then I heard the voice of the Lord saying: “Whom shall I send? Who will go for Us?” And I said: “Here am I. Send me!”

From Isaiah 6. Also in the ESV.

Commentary on Isaiah 6:8

• John Calvin (Reformed), Calvin's Commentaries on Isaiah 6:8: 8. Afterwards I heard the voice of the Lord. The Prophet now begins to discourse about the design of this vision, why God appeared to him with such glorious majesty, in order to ordain him anew as a prophet. It was because he was called to deliver an incredible message about blinding the Jews.
• Matthew Henry (Presbyterian), Matthew Henry's Complete Commentary on Isaiah 6:5-8: Our curiosity would lead us to enquire further concerning the seraphim, their songs and their services; but here we leave them, and must attend to what passed between God and his prophet. Secret things belong not to us, the secret things of the world of angels, but things revealed to and by the prophets, which concern the administration of God's kingdom among men. Now here we have, I.
• John Gill (Reformed Baptist), Exposition of the Old and New Testaments on Isaiah 6:8: Also I heard the voice of the Lord,.... The Targum renders it, the voice of the Word of the Lord, as if it was the second Person, the Word, that was heard speaking; but it seems rather to be the voice of the first Person, the Father: saying, Whom shall I send?
• Jamieson-Fausset-Brown (Reformed), Commentary Critical and Explanatory on the Whole Bible on Isaiah 6:8: I . . . us--The change of number indicates the Trinity (compare Gen 1:26; Gen 11:7). Though not a sure argument for the doctrine, for the plural may indicate merely majesty, it accords with that truth proved elsewhere. Whom . . .