Definition and Significance:
The term "His Sanctuary" refers to the sacred dwelling place of God among His people. In the biblical context, it encompasses the Tabernacle, the Temple in Jerusalem, and the heavenly sanctuary. It signifies God's presence, holiness, and the place where He meets with His people.

Biblical References:

1. The Tabernacle:
The Tabernacle, also known as the Tent of Meeting, was the portable sanctuary used by the Israelites during their wanderings in the wilderness. It was constructed according to divine instructions given to Moses on Mount Sinai. The Tabernacle served as the central place of worship and sacrifice, symbolizing God's presence among His people. Exodus 25:8-9 states, "Then have them make a sanctuary for Me, so that I may dwell among them. You must make it according to all that I will show you—the pattern of the Tabernacle as well as the pattern of all its furnishings."

2. The Temple:
The Temple in Jerusalem, first built by King Solomon, was the permanent structure that replaced the Tabernacle. It became the central place of worship for the Israelites and housed the Ark of the Covenant. The Temple was a symbol of God's enduring presence and His covenant with Israel. In 1 Kings 8:10-11 , it is recorded, "And when the priests came out of the Holy Place, the cloud filled the house of the LORD so that the priests could not stand there to minister because of the cloud; for the glory of the LORD filled the house of the LORD."

3. The Heavenly Sanctuary:
The concept of a heavenly sanctuary is found in the New Testament, particularly in the book of Hebrews. It describes a greater and more perfect tabernacle not made by human hands, where Christ serves as the High Priest. Hebrews 9:11-12 explains, "But when Christ came as high priest of the good things that have come, He went through the greater and more perfect tabernacle that is not made by hands and is not of this creation. He did not enter by the blood of goats and calves, but He entered the Most Holy Place once for all, by His own blood, thus securing eternal redemption."

Theological Themes:

1. God's Presence:
His Sanctuary is fundamentally about God's desire to dwell among His people. It is a place where heaven and earth meet, and where God reveals His glory and holiness. The sanctuary serves as a constant reminder of God's immanence and His willingness to be near His creation.

2. Holiness and Worship:
The sanctuary is a place set apart for worship and reverence. It underscores the holiness of God and the need for His people to approach Him with purity and devotion. The rituals and sacrifices performed in the sanctuary highlight the seriousness of sin and the necessity of atonement.

3. Covenant Relationship:
His Sanctuary is a testament to God's covenant relationship with His people. It is a physical representation of His promises and faithfulness. The sanctuary rituals and the presence of the Ark of the Covenant within it serve as reminders of the laws and commitments between God and Israel.

4. Christ as the Fulfillment:
In the New Testament, Jesus Christ is seen as the fulfillment of the sanctuary's purpose. He is the ultimate High Priest and the perfect sacrifice, rendering the earthly sanctuary's functions complete. Through His death and resurrection, believers have direct access to God, as stated in Hebrews 10:19-22 , "Therefore, brothers, since we have confidence to enter the Most Holy Place by the blood of Jesus, by the new and living way opened for us through the curtain of His body, and since we have a great priest over the house of God, let us draw near with a sincere heart in full assurance of faith."

Conclusion:
The concept of His Sanctuary is central to understanding the relationship between God and His people throughout biblical history. It represents God's desire to dwell among His people, the holiness required to approach Him, and the ultimate fulfillment of these themes in the person and work of Jesus Christ.