Parallel
1 Samuel 20:17
King James Version (1769 Blayney revision, with Apocrypha) · Berean Standard Bible
And Jonathan caused David to swear again, because he loved him (note: Or, by his love towards him): for he loved him as he loved his own soul.
And Jonathan had David reaffirm his vow out of love for him, for Jonathan loved David as he loved himself.