Ps 121:5

“"For there were seated seats for judgment" (ver. 5). This is a wonderful riddle, a wonderful question, if it be not understood. He calleth those seats, which the Greeks call thrones. The Greeks call chairs thrones, as a term of honour. Therefore, my brethren, it is not wonderful if even we should sit on seats, or chairs; but that these seats themselves should sit, when shall we be able to understand this? As if some one should say: let stools or chairs sit here. We sit on chairs, we sit on seats, we sit on stools; the seats themselves sit not. What then meaneth this, "For there were seated seats for judgment"? ...If therefore heaven be the seat of God, and the Apostles are heaven; they themselves are become the seat of God, the throne of God. It is said in another passage: "The soul of the righteous is the throne of wisdom." A great truth, a great truth, is declared; the throne of wisdom is the soul of the righteous; that is, wisdom sitteth in the soul of the righteous as it were in her chair, in her throne, and thence judgeth whatsoever she judgeth. There were therefore thrones of wisdom, and therefore the Lord said unto them, "Ye shall sit upon twelve thrones, judging the twelve tribes of Israel." So they also shall sit upon twelve seats, and they are themselves the seats of God; for of them it is said, "For there were seated seats." Who sat? "Seats." And who are the seats? They of whom it is said, "The soul of the righteous is the seat of wisdom." Who are the seats? The heavens. Who are the heavens? Heaven. What is heaven? That of which the Lord saith, "Heaven is My seat." The righteous then themselves are the seats; and have seats; and seats shall be seated in that Jerusalem. For what purpose? "For judgment." Ye shall sit, He saith, on twelve thrones, O ye thrones, judging the twelve tribes of Israel. Judging whom? Those who are below on earth. Who will judge? They who have become heaven. But they who shall be judged, will be divided into two bodies: one will be on the right hand, the other on the left ...”

“Upon. Or “over.” (Haydock) — The Jews made their sanhedrim superior to the kings, as the Chaldean here insinuates. But the text rather means that both the ecclesiastical and civil courts shall be re-established, and bring an immense concourse of people to the city. (Calmet) — The Church is empowered to pass sentence, (Worthington) and the apostles shall judge both men and angels. (Haydock)”