Mount Zion is the thumb-shaped rise upon which a fortress was built and around which the city of Jesus grew. Though the Jebusites boasted that David would never be able to enter their city, David nevertheless took their stronghold and made it his capital—Jerusalem (2 Samuel 5:6–12; 1 Chronicles 11:4–9). That the Lamb “stood” “on Mount Zion” marks him as the promised Son of David who continued David’s reign (2 Samuel 7:12; Psalm 2:6; Psalm 9:11). Further, the name “Mount Zion” became attached to the temple Solomon built in Jerusalem. The temple, of course, embodied the visible preaching of the gospel as sacrifices were offered, foreshadowing the work Jesus Christ would do to reconcile sinners (assembled in the temple courtyard) with God (who dwelt in the Most Holy Place deep inside the temple). So the name of the place (Mount Zion) came to stand for the gospel itself, the redemption there is in the promised Messiah and the salvation believers have in God (Psalm 14:7; Psalm 20:2; Psalm 53:6) and even for God himself (Psalm 48:12–14; Psalm 50:2).
1 Then I looked, and behold, on Mount Zion stood the Lamb, and with him 144,000 who had his name and his Father’s name written on their foreheads.