It is not so - Jonathan's unwillingness to believe evil of his father is one of the many admirable traits in his character.

My father will do nothing - Jonathan thought that his father could have no evil design against David, because of the oath which he had sworn to himself 1 Samuel 19:6; and at any rate, that he would do nothing against David without informing him.

And he said unto him, God forbid, thou shalt not die,.... He could not believe his father had any such intention; and that if he discovered anything of that kind, it was only when he was in a frenzy, and a melancholy disorder had seized him; and that David had nothing to fear on that head, and that he would secure him from all danger in that respect; the thing was too gross and detestable to be credited:

behold, my father will do nothing, either great or small, but that he will show it me; such an interest had he in him, and in his favour, being his son and heir to his crown, and having done many warlike exploits, which had the more endeared him to him, that he made him privy to all his secret designs, and took his opinion in all matters of moment and importance:

and why should my father hide this thing from me? his design of taking away the life of David, if he had really formed one:

it is not so; Jonathan concluded, from his ignorance of it, there was nothing in it, and that it was only a surmise of David's; and yet it is strange that Jonathan should know nothing of the messengers being sent to David's house to take him, and of others sent to Naioth after him, and of Saul's going there himself with such a design; and if he did know anything of the matter, he made the best of it to David, partly to allay his fears, and partly that his father might not appear so black and vile as he really was.

Jonathan endeavoured to pacify him: "Far be it! thou shalt not die: behold, my father does nothing great or small (i.e., not the smallest thing; cf. 1 Samuel 25:36 and Numbers 22:18) that he does not reveal to me; why should my father hide this thing from me? It is not so." The לו after הנּה stands for לא: the Chethibh עשׂה is probably to be preferred to the Keri יעשׂה, and to be understood in this sense: "My father has (hitherto) done nothing at all, which he has not told to me." This answer of Jonathan does not presuppose that he knew nothing of the occurrences described in 1 Samuel 19:9-24, although it is possible enough that he might not have been with his father just at that time; but it is easily explained from the fact that Saul had made the fresh attack upon David's life in a state of madness, in which he was no longer master of himself; so that it could not be inferred with certainty from this that he would still plot against David's life in a state of clear consciousness. Hitherto Saul had no doubt talked over all his plans and undertakings with Jonathan, but he had not uttered a single word to him about his deadly hatred, or his intention of killing David; so that Jonathan might really have regarded his previous attacks upon David's life as nothing more than symptoms of temporary aberration of mind.

And he said unto him, God forbid; thou shalt not die: behold, my father will do nothing either great or small, but that he will show it me: and why should my father hide this thing from me? it is not so.

20:2 Is it not so - For Jonathan gave credit to his father's oath, chap.19:6.

shew...: Heb. uncover mine ear

20:1-10 The trials David met with, prepared him for future advancement. Thus the Lord deals with those whom he prepares unto glory. He does not put them into immediate possession of the kingdom, but leads them to it through much tribulation, which he makes the means of fitting them for it. Let them not murmur at his gracious appointment, nor distrust his care; but let them look forward with joyful expectation to the crown which is laid up for them. Sometimes it appears to us that there is but a step between us and death; at all times it may be so, and we should prepare for the event. But though dangers appear most threatening, we cannot die till the purpose of God concerning us is accomplished; nor till we have served our generation according to his will, if we are believers. Jonathan generously offers David his services. This is true friendship. Thus Christ testifies his love to us, Ask, and it shall be done for you; and we must testify our love to him, by keeping his commandments.