2 Chronicles 3:8

Now he made the room of the Holy of Holies: its length equaling the width of the house was twenty cubits, and its width was twenty cubits; and he overlaid it with 600 talents of fine gold.

Exodus 26:33

You shall hang the veil from the hooks [that connect the curtains together], and you shall bring the ark of the Testimony there within the veil. The veil shall separate for you the Holy Place and the Holy of Holies.

1 Kings 6:16

He built twenty cubits on the rear of the house with boards of cedar from the floor to the ceiling; he built its interior as the [inner] sanctuary, the Holy of Holies.

1 Kings 6:19-20

Then he prepared the Holy of Holies within the house in order to put the ark of the covenant of the Lord there.

Hebrews 9:3

Behind the second veil there was another tabernacle [the inner one or second section] known as the Holy of Holies,

Hebrews 9:9

for this [first or outer tabernacle] is a symbol [that is, an archetype or paradigm] for the present time. Accordingly both gifts and sacrifices are offered which are incapable of perfecting the conscience and renewing the [inner self of the] worshiper.

Hebrews 10:19

Therefore, believers, since we have confidence and full freedom to enter the Holy Place [the place where God dwells] by [means of] the blood of Jesus,

Treasury of Scripture Knowledge

Summary

And he made the most holy house, the length whereof was according to the breadth of the house, twenty cubits, and the breadth thereof twenty cubits: and he overlaid it with fine gold, amounting to six hundred talents.

Bible References

The most holy

Exodus 26:33
You shall hang the veil from the hooks [that connect the curtains together], and you shall bring the ark of the Testimony there within the veil. The veil shall separate for you the Holy Place and the Holy of Holies.
1 Kings 6:19
Then he prepared the Holy of Holies within the house in order to put the ark of the covenant of the Lord there.
Hebrews 9:3
Behind the second veil there was another tabernacle [the inner one or second section] known as the Holy of Holies,
Hebrews 10:19
Therefore, believers, since we have confidence and full freedom to enter the Holy Place [the place where God dwells] by [means of] the blood of Jesus,