Then Jonathan
Yhownathan (yeh-ho-naw-thawn')
Jehovah-given; Jehonathan, the name of four Israelites -- Jonathan.
and David
David (daw-veed')
loving; David, the youngest son of Jesse -- David.
made
karath (kaw-rath')
to cut (off, down or asunder); by implication, to destroy or consume; specifically, to covenant
a covenant
briyth (ber-eeth')
a compact (because made by passing between pieces of flesh) -- confederacy, (con-)feder(-ate), covenant, league.
because he loved
'ahabah (a-hab-aw)
love.
him as his own soul
nephesh (neh'-fesh)
a breathing creature, i.e. animal of (abstractly) vitality; used very widely in a literal, accommodated or figurative sense (bodily or mental)