Cry thou - The vision was not for the prophet alone. What he saw and heard, that he was to proclaim to others. The vision, which he now saw alone, was to be the basis and substance of his subsequent preaching Jonah 1:2; Isaiah 40:2, Isaiah 40:6, whereby he was to encourage his people to persevere.
I am jealous for Jerusalem - Literally, “I have been,” not now only but in time past even when I did not show it, “and am jealous”, with the tender love which allows not what it loves to be injured . The love of God, until finally shut out, is unchangeable, He pursues the sinner with chastisements and scourges in His love, that he may yet be converted and live . But for God’s love to him and the solicitations of His grace, while yet impenitent and displeasing Him, he could not turn and please Him.
And for Zion - Which especially He had chosen to put His Name there, and there to receive the worship of His people; “the hill which God desired to dwell in” Psalms 68:16, “which He loved” (Psalms 78:68; add Psalms 132:13-14). Dionysius: “With great and special love have I loved the people of the Jews and what pertained to them, and out of that love have I so diligently and severely corrected her excesses, that she may be more careful for the time to come, as a husband corrects most sharply a wife most dear to him, if she be unfaithful. Whence in the book of Maccabees it is written, “It is a token of His great goodness, when wicked doers are not suffered any long time, but are immediately punished. For not as with other nations, whom the Lord patiently forbeareth to punish, till they be come to the fullness of their sins, so dealeth He with us; lest, being come to the height of sin, afterward He should take vengeance of us. And therefore He never withdraweth His mercy from us, and though He punisheth with adversity, yet doth He never forsake His people” (2 Macc. 6:13-16).