made a covenant

1 Samuel 20:8-17, 42
Therefore deal faithfully with your servant, for you have brought me into a covenant with you before the LORD. If there is iniquity in me, then kill me yourself; why should you bring me to your father?" . . .

1 Samuel 23:18
So the two of them made a covenant before the LORD. And David remained in Horesh, while Jonathan went home.

2 Samuel 9:1-3
Then David asked, "Is there anyone left from the house of Saul to whom I can show kindness for the sake of Jonathan?" . . .

2 Samuel 21:7
Now the king spared Mephibosheth son of Jonathan, the son of Saul, because of the oath before the LORD between David and Jonathan son of Saul.