1 Samuel 18:3

And Jonathan and David will cut out a covenant in his loving him as his soul

1 Samuel 20:8-17

And do thou mercy with thy servant; for into a covenant of Jehovah thou didst bring thy servant with thee: and if there is iniquity in me, do thou kill me; and wherefore wilt thou bring me even to thy father?

1 Samuel 20:42

And Jonathan will say to David, Go for peace, for we sware, we two, in the name of Jehovah, saying, Jehovah will be between me and between thee, and between my seed and between thy seed, even forever. And he will rise and go: and Jonathan came to the city.

1 Samuel 23:18

And they two will cut out a covenant before Jehovah: and David dwelt in the thicket, and Jonathan went to his house.

2 Samuel 9:1-3

And David will say, Is there yet any which was left to the house of Saul? and I will do with him mercy for sake of Jonathan.

2 Samuel 21:7

And the king will spare upon Mephibosheth, son of Jonathan, son of Saul, on account of the oath of Jehovah which was between them, betwen David and between Jonathan, son of Saul.

Treasury of Scripture Knowledge

Summary

Then Jonathan and David made a covenant, because he loved him as his own soul.

Bible References

General references

Genesis 21:32
And they will make a covenant, at the well of the oath, and Abimelech will rise up, and Phicol, the leader of his army, and they will turn back to the land of the Philistines,
1 Samuel 23:18
And they two will cut out a covenant before Jehovah: and David dwelt in the thicket, and Jonathan went to his house.
Proverbs 17:17
A friend loves in all time, and a brother shall be born for straits.