Proverbs 25:3

As heaven is to height and the earth is to depth, so [is] the heart of kings--there is no searching.

1 Kings 4:29

God gave wisdom to Solomon and very great discernment, as well as {breadth of understanding}, as the sand which is on the edge of the seashore.

Psalm 103:11

For as [the] heavens are high above the earth, [so] his loyal love prevails over those who fear him.

Isaiah 7:11

"Ask for a sign for yourself from Yahweh God; make [it] deep [as] Sheol or make [it] high as above."

Isaiah 55:9

"For [as] [the] heavens are {higher} than [the] earth, so my ways are {higher} than your ways, and my thoughts than your thoughts.

Romans 8:39

nor height, nor depth, nor any other created thing, will be able to separate us from the love of God that is in Christ Jesus our Lord.

1 Peter 1:7

so that the genuineness of your faith, more valuable than gold that is passing away, but is tested by fire, may be found to [result in] praise and glory and honor at the revelation of Jesus Christ,

Treasury of Scripture Knowledge

Summary

The heaven for height, and the earth for depth, and the heart of kings is unsearchable.

Is unsearchable

General references

Bible References

Heaven

Psalm 103:11
For as [the] heavens are high above the earth, [so] his loyal love prevails over those who fear him.
Isaiah 7:11
"Ask for a sign for yourself from Yahweh God; make [it] deep [as] Sheol or make [it] high as above."
Isaiah 55:9
"For [as] [the] heavens are {higher} than [the] earth, so my ways are {higher} than your ways, and my thoughts than your thoughts.
Romans 8:39
nor height, nor depth, nor any other created thing, will be able to separate us from the love of God that is in Christ Jesus our Lord.

Is unsearchable

1 Kings 4:29
God gave wisdom to Solomon and very great discernment, as well as {breadth of understanding}, as the sand which is on the edge of the seashore.
1 Peter 1:7
so that the genuineness of your faith, more valuable than gold that is passing away, but is tested by fire, may be found to [result in] praise and glory and honor at the revelation of Jesus Christ,

General references

Isaiah 55:8
"For my thoughts [are] not your thoughts, and your ways [are] not my ways," {declares} Yahweh.