This verse is an introduction to a long section of direct speech from the mouth of the LORD covering verses 8-13. It sets forth the topic of the following verses, namely, the day of the LORD.
To be silent in the presence of God is a sign of reverence and is mentioned elsewhere in this connection (Hab 2.20; Zech 2.13). The clause Be silent before the LORD GOD may be expressed idiomatically in certain languages as “Be silent in front of the face of the Lord GOD,” or “Do not say anything when you are in front of the Lord GOD’s face,” or “Do not say anything when you are in the place where the Lord GOD is.”
For the spelling of GOD with capital letters, see the comments on Habakkuk 3.19.
The day of the LORD: Good News Translation expands this expression to make the full meaning clear by saying “The day … when the LORD will sit in judgment.” Other possible translation models are “… sit to judge people” or “… cut judgment against the people of the world.” The day … is at hand may also be expressed as “The day when … will come very soon” or “The time when … will come very soon.” Good News Translation also reverses the order of the first two clauses in Hebrew, giving the reason (the nearness of judgment) before the command which follows from it, “so be silent in his presence.”
The second half of verse 7 uses the technical language of sacrificial ritual. The Hebrew roots underlying the words sacrifice, consecrated, and guests all appear in 1 Sam 16.5, but whereas there a literal sacrifice is being described, here the terms have a figurative meaning. The judgment of God is pictured as a sacrifice in which God’s own people are slaughtered by their enemies. When guests at a sacrifice were consecrated, this involved ritual purification and also constituted official invitation. Here the focus is on the invitation, and so Good News Translation translates “has invited.” The guests in this case are enemies who will punish the people of Judah, and Good News Translation “enemies” makes this meaning explicit. Good News Translation makes the identification of all the participants clear by saying “The LORD is preparing to sacrifice his people and has invited enemies to plunder Judah.” One can also make the event or action implied in the word sacrifice more explicit by saying “to slaughter his people as animals are killed in sacrifice.” (Compare with Jehu’s slaughter of the worshipers of Baal in 2 Kgs 10.18-27.)
Quoted with permission from Clark, David J. & Hatton, Howard A. A Handbook on the Book of Zephaniah. (UBS Helps for Translators). New York: UBS, 1989. For this and other handbooks for translators see here .