1 Samuel 20:8

A covenant of the Lord with thee. — It may at first sight seem strange that we have these last meetings of David and Jonathan told us in such detail — the speaker’s very words quoted, and so many apparently trivial circumstances related.

The question, too, might be asked: Whence did the compiler of the book derive his intimate acquaintance with what took place at these meetings, when David was alone with Jonathan? But the difficulties are only surface ones, for we must never forget how intensely interesting to the chosen people were all the circumstances connected with their loved king’s life — never lose sight of the deathless interest with which they would hear and read the particulars of David’s rise through great suffering and long trial to the throne; and this period here related in such detail was the turning-point of a grand career. From this moment, David’s way diverged from the every-day life of ordinary duty and prosperity, and became, during a long and weary period, for him the way of almost uninterrupted suffering. The way of suffering and of trial is in all ages the royal road to true greatness. As to the source whence the compiler of the book derived his knowledge of what passed at these last meetings of the two friends, Ewald suggests that when in after years David drew to his Court the posterity of Jonathan, he often told them himself of these last events before their separation (events with which no one but the two friends could be acquainted).

Slay me thyself. — “This supposes that Jonathan had the right to inflict capital punishment for crimes against his father as king.” — Lange. This was David’s last earnest request to the prince. If Jonathan felt there was any truth in the charges brought against him by Saul — if he deemed his friend a traitor to the reigning dynasty — let him slay the betrayer himself there and then.