1 Samuel 18:2

And it came to pass, when he had made an end of speaking unto Saul, that the soul of Jonathan was knit with the soul of David, and Jonathan loved him as his own soul.

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

And Jonathan stripped himself of the robe that was upon him, and gave it to David, and his garments, even to his sword, and to his bow, and to his girdle.

And David went out whithersoever Saul sent him, and behaved himself wisely: and Saul set him over the men of war, and he was accepted in the sight of all the people, and also in the sight of Saul's servants.