New Revised Standard Version
Jonathan made David swear again by his love for him; for he loved him as he loved his own life.

Contemporary English Version
Jonathan thought as much of David as he did of himself, so he asked David to promise once more that he would be a loyal friend.

New American Bible
And in his love for David, Jonathan renewed his oath to him, because he loved him as he loved himself.

Douay-Rheims Bible
And Jonathan swore again to David, because he loved him: for he loved him as his own soul.

And Jonathan swore again to David, because he loved him: for he loved him as his own soul.

because he loved him.

1 Samuel 18:1,3 And it came to pass, when he had made an end of speaking to Saul, the son of Jonathan was knit with the soul of David, and Jonathan loved him as his own soul. . . .

Deuteronomy 13:6 If thy brother the son of thy mother, or thy son, or daughter, or thy wife that is in thy bosom, or thy friend, whom thou lovest as thy own soul, would persuade thee secretly, saying: Let us go, and serve strange gods, which thou knowest not, nor thy fathers,

2 Samuel 1:26 I grieve for thee, my brother Jonathan: exceeding beautiful, and amiable to me above the love of women. As the mother loveth her only son, so did I love thee.

Proverbs 18:24 A man amiable in society, shall be more friendly than a brother.