“In that day.” “That day” is the “day of Yahweh.” Here in Zephaniah 3:11 and also in Zephaniah 3:16, the emphasis of “that day” is not the wrath of God, as was the case in the other occurrences of “that day” and the “Day of Yahweh” in the book of Zephaniah, but rather this part of “that day” refers to the peaceful reign of Christ on earth after God’s wrath has passed. The “Day of Yahweh” has many parts, and different parts are emphasized at different times (see commentary on Zeph. 1:7).
“you will not be put to shame.” The verb is feminine singular, and thus the “you” is singular, referring to Jerusalem, and thus by metonymy the people who live there. In the Millennial Kingdom, Jerusalem will be exalted (cp. Isa. 2:1-3; Micah 4:1-2; Jer. 33:15-16).
“remove from your midst.” In the coming Tribulation, Armageddon, and judgments, especially the Sheep and Goat Judgment, the proud and arrogant people will be removed from Jerusalem, indeed, at the start of Christ’s Millennial Kingdom they will be removed from the whole earth. The Tribulation and Armageddon will kill many of them, and those who survive will be weeded out and thrown into the Lake of Fire at the Sheep and Goat Judgment (Matt. 25:31-46; see commentary on Matt. 25:32). After the judgment, the people who will be left will inherit the earth, just as Jesus taught (Zeph. 3:12; Matt. 5:5). [For more on the Tribulation, see commentary on Dan. 12:1. For more on the Millennial Kingdom of Christ, see Appendix 3, “Christ’s Future Kingdom on Earth’].
“your people.” The Hebrew text makes it clear that the proud people are Jews, not just Gentiles who live in the midst of the Jews. Many of God’s chosen people rejected God. It has always been that way and still is today.
“rejoice in their pride.” The Hebrew phrase refers to those people who are defiantly proud, they will not humble themselves and obey God. The phrase is translated differently in the different English versions as they try to capture the meaning of the Hebrew text: “take joy in arrogance” (CJB); “your proud, arrogant people” (HCSB); “proudly exultant ones” (ESV); “rejoice in thy pride” (KJV); “those who proudly boast” (NET); “rejoice in their pride” (NIV84); “arrogant boasters” (NIV2011).
From God’s perspective, a proud person is someone who will not humble themselves and submit to the rule of God. A humble person bows the knee to Jesus Christ and recognizes his lordship. A proud person might be a “nice guy,” but in their heart they are self-sufficient. The most recognized definition of a proud person is a person who outwardly shows that they have an excessively high opinion of themselves and/or are self-important, but from God’s perspective a proud person is also one who is satisfied with themselves and their own qualities and achievements and does not or will not recognize God’s place and lordship in their lives. Thus, Zephaniah 1:6 includes among the people who will be removed “those who have not sought Yahweh or asked anything of him.” People who do not recognize the lordship of God and Christ have no place in their kingdom.