Who is blind, but my servant? or deaf, as my messenger that I sent? who is blind as he that is perfect, and blind as the LORD's servant?
Who is blind, but my servant? - namely, Israel. Who of the pagan is so blind? Considering Israel's high privileges, the pagan's blindness was as nothing compared with that of Israelite idolaters.
Or deaf, as my messenger (that) I sent? Israel was designed by God to be the herald of His truth to other nations.
Who (is) blind as (he that is) perfect? - furnished with institutions, civil and religious, suited to their perfect well-being. Compare the title, 'Jeshurun,' the perfect one, applied to Israel (cf. Isaiah 44:2), as the type of Messiah (Vitringa). Or translate х mªshulaam (H4918)], the friend of God, which Israel was by virtue of descent from Abraham, who was so called (Isaiah 41:8) (Gesenius). So Grotius, 'he that is in covenant with God
... the people with whom God has made a covenant of eternal peace and all blessing.' So the Mohammedans call themselves, from the kindred term Mussulmen. The language, "my servant" (cf. Isaiah 42:1), "messenger" (Malachi 3:1), "perfect" (Romans 10:4; Hebrews 2:10; 1 Peter 2:22), can, in the full antitypical sense, only apply to Christ. So Isaiah 42:21 plainly refers to Him. "Blind" and "deaf" in His case refer to His endurance of suffering and reproach, as though He neither saw nor heard (Psalms 38:13-14). Thus, there is a transition by contrast from the moral blindness of Israel (Isaiah 42:18) to the patient blindness and deafness of Messiah (Horsley).