Rabbi Azarya in the name of Rabbi Yehuda bar Simon interpreted the verse regarding Isaiah. Isaiah said: ‘I was at leisure in my study hall, and I heard the voice of the Holy One blessed be He saying: “Whom shall I send and who will go for us?” (Isaiah 6:8). [God said:] I sent Micah, and they were striking him on his cheek. That is what is written: “With a rod they strike on the cheek” (Micah 4:14).
I sent Amos and they would call him stutterer, as Rabbi Pinḥas said: Why was his name called Amos? It was because he was cumbrous [amus] of tongue. Now, “whom shall I send and who will go for us?” “I said: Here I am, send me” (Isaiah 6:8).
The Holy One blessed be He said to him: ‘Isaiah, My children, they are troublesome and insubordinate. If you accept upon yourself to be demeaned and to be stricken by My children, you will go on My mission, but if not, you will not go on My mission.’ He said to Him: ‘[I am willing to accept] this condition; “I gave my body to those who smite and my cheeks to those who pluck” (Isaiah 50:6). But I am not worthy to go on a mission to Your children.’
The Holy One blessed be He said to him: ‘Isaiah, “you love righteousness,” you love to vindicate My children; “and detest wickedness,” you detest condemning them. “Therefore, God your God, has anointed you.”’ What is “over your counterparts”? He said to him: ‘As you live, all the prophets received their prophetic capacity from a prophet: “He drew from the spirit that was upon him [and placed it upon the seventy elders…they prophesied]” (Numbers 11:25).
“They said: The spirit of Elijah has rested upon Elisha” (II Kings 2:15). But you, from the mouth of the Holy One blessed be He: “The spirit of the Lord God is upon me, because the Lord has anointed…” (Isaiah 61:1). As you live, all the prophets prophesy simple prophecies, but you [will receive] compound prophecies of consolation: “Awaken, awaken, [clothe yourself with splendor…]” (Isaiah 51:9), “awaken yourself, awaken yourself, [arise, O Jerusalem…]” (Isaiah 51:17), “I will be gladdened [sos asis]” (Isaiah 61:10), “I, I [am He who comforts you…]” (Isaiah 51:12), “Comfort, comfort [My people, says your God]”’ (Isaiah 40:1).