Albert Barnes Commentary Isaiah 16:5

"And a throne shall be established in lovingkindness; and one shall sit thereon in truth, in the tent of David, judging, and seeking justice, and swift to do righteousness." — Isaiah 16:5 (ASV)

And in mercy—In benignity; kindness; benevolence.

Shall the throne be established—The throne of the king of Judah. That is, he who will sit upon the throne of David will be disposed to repay the kindness now sought from Moab, and will be able to do it.

And he shall sit upon it—The king of Israel.

In truth—In faithfulness; that is, he will be true and faithful. His character will be such that he will do justice, and will furnish protection and aid to the Moabites, if they now receive the fugitives of Israel.

In the tabernacle of David—In the dwelling place; the palace of David; for so the word “tabernacle, or tent” (אהל 'ôhel') seems to be used here. It means “temple” in (Ezekiel 41:1). It denotes a habitation, or dwelling place, in general, in (Proverbs 14:11), (Psalms 52:7), and (Psalms 91:10).

The palace, court, or “citadel” of David was on Mount Zion. The sense here is that the king to whom Israel refers would be a worthy successor of David—just, true, faithful, benevolent, and disposed to repay the favors now sought from Moab.

Seeking judgment—Anxious to do right, and seeking an opportunity to recompense those who had shown any favor to the people of the Jews. Moab, therefore, if she would now afford protection to the Jews, might be certain of a recompense.

And hasting righteousness—Not tardy and slow in doing what should be done; anxious to do justice to all. It is implied here also that a king who would be so just, and so anxious to do “right” to all, would not only be ready to show kindness to the Moabites if they protected the fugitives of Judea, but would also be disposed to do “right” if they refused that protection—that is, would be disposed to inflict “punishment” on them.

Therefore, by both the hope of the protection and favor of the king of the Jews and by the dread of punishment, the prophet endeavors to persuade Moab to now secure their favor by granting protection to their exiles.