Ezekiel 41:4

He measured the length [of the interior of the inner sanctuary], twenty cubits, and the width, twenty cubits, opposite the nave (outer sanctuary); and he said to me, “This is the Most Holy Place.”

1 Kings 6:20

The Holy of Holies was twenty cubits in length, twenty cubits in width, and twenty cubits in height (a cube), and he overlaid it with pure gold. He also overlaid the cedar altar [with gold].

Hebrews 9:3-8

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

Exodus 26:33-34

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.

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.

1 Kings 6:5

Against the wall of the house he built extensions around the walls of the house, around both the main room (Holy Place) and the Holy of Holies; and he made side chambers all around.

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.

Revelation 21:16

The city is laid out as a square, its length being the same as its width; and he measured the city with his rod—twelve thousand stadia (about 1,400 miles); its length and width and height are equal.

Treasury of Scripture Knowledge

Summary

So he measured the length thereof, twenty cubits; and the breadth, twenty cubits, before the temple: and he said unto me, This is the most holy place.

Bible References

Twenty cubits

1 Kings 6:20
The Holy of Holies was twenty cubits in length, twenty cubits in width, and twenty cubits in height (a cube), and he overlaid it with pure gold. He also overlaid the cedar altar [with gold].
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.
Revelation 21:16
The city is laid out as a square, its length being the same as its width; and he measured the city with his rod—twelve thousand stadia (about 1,400 miles); its length and width and height are equal.

This

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.
Hebrews 9:3
Behind the second veil there was another tabernacle [the inner one or second section] known as the Holy of Holies,