Footstool - Vine's Expository Dictionary of New Testament Words
Footstool
[ 1,,G5286, hupopodion ]from hupo, under," and pous, "a foot," is used
(a) literally in James 2:3,
(b) metaphorically, of the earth as God's "footstool," Matthew 5:35; of the foes of the Lord, Matthew 22:44 (in some mss.); Mark 12:36, "underneath" (in some mss.); Luke 20:43; Acts 2:35; Acts 7:49; Hebrews 1:13; Hebrews 10:13. The RV, adhering to the literal rendering, translates the phrase "the footstool of My (Thy, His) feet," for the AV, "My (etc.) footstool," but in Matthew 22:44, "(till I put Thine enemies) underneath thy feet."