1 Samuel 20:17

and Jonathan addeth to cause David to swear, because he loveth him, for with the love of his own soul he hath loved him.

1 Samuel 18:1

And it cometh to pass, when he finisheth to speak unto Saul, that the soul of Jonathan hath been bound to the soul of David, and Jonathan loveth him as his own soul.

1 Samuel 18:3

And Jonathan maketh -- also David -- a covenant, because he loveth him as his own soul,

Deuteronomy 13:6

When thy brother -- son of thy mother, or thy son, or thy daughter, or the wife of thy bosom, or thy friend who is as thine own soul -- doth move thee, in secret, saying, Let us go and serve other gods -- (which thou hast not known, thou and thy fathers,

2 Samuel 1:26

I am in distress for thee, my brother Jonathan, Very pleasant wast thou to me; Wonderful was thy love to me, Above the love of women!

Proverbs 18:24

A man with friends is to show himself friendly, And there is a lover adhering more than a brother!

Treasury of Scripture Knowledge

Summary

And Jonathan caused David to swear again, because he loved him: for he loved him as he loved his own soul.

General references

Bible References

Because he loved him

1 Samuel 18:1
And it cometh to pass, when he finisheth to speak unto Saul, that the soul of Jonathan hath been bound to the soul of David, and Jonathan loveth him as his own soul.
Deuteronomy 13:6
When thy brother -- son of thy mother, or thy son, or thy daughter, or the wife of thy bosom, or thy friend who is as thine own soul -- doth move thee, in secret, saying, Let us go and serve other gods -- (which thou hast not known, thou and thy fathers,
2 Samuel 1:26
I am in distress for thee, my brother Jonathan, Very pleasant wast thou to me; Wonderful was thy love to me, Above the love of women!
Proverbs 18:24
A man with friends is to show himself friendly, And there is a lover adhering more than a brother!

General references

1 Samuel 23:18
And they make a covenant both of them before Jehovah; and David abideth in the forest, and Jonathan hath gone to his house.
Proverbs 17:17
At all times is the friend loving, And a brother for adversity is born.