1 Samuel 18:3

3 So Jonathan made a pledge of mutual loyalty with David because he loved him as much as [he loved] himself.

1 Samuel 18:3 Meaning and Commentary

1 Samuel 18:3

Then Jonathan and David made a covenant
A covenant of friendship; entered into a solemn agreement to keep up and maintain a cordial respect to each other, and to support each other's interest both in life and after death, whoever was the survivor; and in consequence of this David had a friend at court, when Saul fell out with him, and who pleaded his cause, and discovered his father's plots, and was the means of preserving David's life:

because he loved him as his own soul;
so that this covenant was not founded in mere words, but in sincere and cordial affection, and was lasting and inviolable.

1 Samuel 18:3 In-Context

1 David finished talking to Saul. After that, Jonathan became David's closest friend. He loved David as much as [he loved] himself.

2 (From that day on Saul kept David [as his servant] and didn't let him go back to his family.)

3 So Jonathan made a pledge of mutual loyalty with David because he loved him as much as [he loved] himself.

4 Jonathan took off the coat he had on and gave it to David along with his battle tunic, his sword, his bow, and his belt.

5 David was successful wherever Saul sent him. Saul put him in charge of the fighting men. This pleased all the people, including Saul's officials.