Excerpts from 1 Samuel
18:1 (TLB): After King Saul had finished his conversation with David, David met Jonathan, the king’s son, and there was an immediate bond of love between them. Jonathan swore to be his blood brother
The literal translation of this verse is something like Jonathan's soul was tied to David's soul. Most translations I looked at are along the lines of Jonathan's soul was bound to David's soul.
The first thing that most people might think of when reading this is that the two are lovers, like the Red String of Fate. However, the fact that the author used this language to describe friends is what truly astounds me. It's one of the most beautiful things I've ever read, perhaps even more beautiful than Songs of Solomon.
20:42a (ERV): Then Jonathan said to David, “Go in peace. We have taken an oath in the Lord’s name to be friends forever.