Ezekiel 41:4

And 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.

1 Kings 6:20

And within the oracle was a space of twenty cubits in length, and twenty cubits in breadth, and twenty cubits in the height thereof; and he overlaid it with pure gold: and he covered the altar with cedar.

Hebrews 9:3-8

And after the second veil, the tabernacle which is called the Holy of holies;

Exodus 26:33-34

And thou shalt hang up the veil under the clasps, and shalt bring in thither within the veil the ark of the testimony: and the veil shall separate unto you between the holy place and the most holy.

2 Chronicles 3:8

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

1 Kings 6:5

And against the wall of the house he built stories round about, against the walls of the house round about, both of the temple and of the oracle; and he made side-chambers round about.

1 Kings 6:16

And he built twenty cubits on the hinder part of the house with boards of cedar from the floor unto the walls of the ceiling : he built them for it within, for an oracle, even for the most holy place.

Revelation 21:16

And the city lieth foursquare, and the length thereof is as great as the breadth: and he measured the city with the reed, twelve thousand furlongs: the length and the breadth and the height thereof 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
And within the oracle was a space of twenty cubits in length, and twenty cubits in breadth, and twenty cubits in the height thereof; and he overlaid it with pure gold: and he covered the altar with cedar.
2 Chronicles 3:8
And he made the most holy house: the length thereof, according to the breadth of the house, was twenty cubits, and the breadth thereof twenty cubits; and he overlaid it with fine gold, amounting to six hundred talents.
Revelation 21:16
And the city lieth foursquare, and the length thereof is as great as the breadth: and he measured the city with the reed, twelve thousand furlongs: the length and the breadth and the height thereof are equal.

This

Exodus 26:33
And thou shalt hang up the veil under the clasps, and shalt bring in thither within the veil the ark of the testimony: and the veil shall separate unto you between the holy place and the most holy.
Hebrews 9:3
And after the second veil, the tabernacle which is called the Holy of holies;

American Standard Version Public Domain