Scofield Reference Notes, 1917 Edition1 Chronicles 11

castle of Zion Heb. castle.

(1) Zion, the ancient Jebusite stronghold, is the southwest eminence in Jerusalem, called in Scripture the city of David, and associated with the Davidic royalty both historically and prophetically 1 Chronicles 11:7; Psalms 2:6; Isaiah 2:3. The word is often used of the whole city of Jerusalem considered as the city of God Psalms 48:2,3 especially in passages referring to the future kingdom-age ; Isaiah 1:27; 2:3; 4:1-6; Joel 3:16; Zechariah 1:16,17; 8:3-8; Romans 11:26. In Hebrews 12:22 the word is used symbolically of heaven.

(2) In Deuteronomy 4:48 the name is given to a projection or peak of Mount Hermon.