Stool
The stool of UPDV usage is almost entirely the footstool — the low rest beneath the feet of a seated dignitary — and is used figuratively for whatever the speaker fits beneath the feet of an enthroned figure. The references group under three frames: the earth as Yahweh's footstool, the temple and sanctuary as his footstool, and the enemies of the right-hand-seated Lord as the footstool he is given.
The Earth as Yahweh's Footstool
Yahweh opens his cosmic-house declaration in Isaiah by pairing throne and footstool against the heaven and the earth: "Thus says Yahweh, Heaven is my throne, and the earth is my footstool: what manner of house will you⁺ build to me? And what place will be my rest?" (Isa 66:1). The footstool-object is the earth itself; the throne-counterpart is the heaven; and the paired house-and-rest rhetorical-questions are addressed to a plural audience (⁺) that might claim to build him a house adequate to his scale. The earth-wide footrest defeats any temple-scale rest-claim.
The Temple and Sanctuary as Footstool
Set against the heaven-throne / earth-footstool of Isaiah, a second figure runs in the opposite direction: the sanctuary site itself is named as Yahweh's footstool. David, addressing the assembly about his unbuilt temple, frames the project as a paired ark-and-footstool work: "it was in my heart to build a house of rest for the ark of the covenant of Yahweh, and for the footstool of our God; and I had made ready for the building" (1Ch 28:2). The footstool-of-our-God here stands alongside the ark-of-the-covenant as a sanctuary-worthy referent.
The same footstool-figure carries through to the worship summons of the Psalter. The exalt⁺-Yahweh call places the worshippers at his footstool: "Exalt⁺ Yahweh our God, And worship at his footstool: He is holy" (Ps 99:5). Psalm 132 makes the same move with a pilgrimage cadence: "We will go into his tabernacles; We will worship at his footstool" (Ps 132:7). In both, the footstool is the site at which the commanded exaltation is enacted.
When that sanctuary-footstool is forfeit, Lamentations names it as the thing the Lord has not remembered: "How has the Lord covered the daughter of Zion with a cloud in his anger! He has cast down from heaven to the earth the beauty of Israel, And has not remembered his footstool in the day of his anger" (La 2:1). Zion as Yahweh's footstool is the figure governing the loss.
Enemies as the Footstool of Christ
The third movement runs through Psalm 110 and the New Testament texts that quote it. The psalm addresses an enthronement: "A Psalm of David. Yahweh says [by his Speech] to my Lord, Sit at my right hand, until I make your enemies a stool for your feet" (Ps 110:1). The enthroning-call is the Sit-at-my-right-hand command; the agent of the stool-making is Yahweh himself; and the footstool's constitutive material is the enemy-class.
Jesus quotes the same psalm in his question about the Christ. In Mark, the wording is "Yahweh said to my Lord, Sit at my right hand, Until I set your enemies under your feet" (Mark 12:36). In Luke, the citation runs closer to Psalm 110's own footstool-figure: "For David himself says in the Book of Psalms, Yahweh said to my Lord, Sit at my right hand, Until I make your enemies the footstool of your feet" (Luke 20:42-43).
Hebrews twice presses Psalm 110 into a point about the right-hand session of the Son. In contrast with the angels — to none of whom is such a thing said — the writer asks: "But of which of the angels has he said at any time, Sit at my right hand, Until I make your enemies the footstool of your feet?" (Heb 1:13). And later, of the seated Son's expectation between his offering and the consummation: "from now on expecting until his enemies are made the footstool of his feet" (Heb 10:13). The footstool here is the destined fitting of the enemy-class beneath the feet of the right-hand-seated Son, a work the Father has pledged.