Jonathan took off the robe he was wearing and gave it to David, along with his tunic, and even his sword, his bow and his belt.
Relationships call for vulnerability. Jonathan gave over to David his weapons. These were the things he used to defend himself and attack his enemies. He left himself vulnerable to David because he trusted him. In our relationships we're to give up our weapons of defense and trust the other person to look out for our well-being. This is God's calling for us, the only way to find peace and joy in those relationships.