12 Then Jonathan said to David, "I swear by the Lord, the God of Israel, that I will surely sound out my father by this time the day after tomorrow! If he is favorably disposed toward you, will I not send you word and let you know?

Matthew Henry's Commentary on 1 Samuel 20:12

Commentary on 1 Samuel 20:11-23

(Read 1 Samuel 20:11-23)

Jonathan faithfully promises that he would let David know how he found his father affected towards him. It will be kindness to ourselves and to ours, to secure an interest in those whom God favours, and to make his friends ours. True friendship rests on a firm basis, and is able to silence ambition, self-love, and undue regard for others. But who can fully understand the love of Jesus, who gave himself as a sacrifice for rebellious, polluted sinners! how great then ought to be the force and effects of our love to him, to his cause, and his people!