1 Samuel 20:5

And David said unto Jonathan
Moved that the following method might be taken as a trial of the disposition of Saul's mind towards David:

behold, tomorrow [is] the new moon;
the first day of the month, which was kept solemnly with burnt offerings and peace offerings, see ( Numbers 10:10 ) ( 28:11 ) . Some say ^F18 this feast was not kept for the new moon, but because it was the day of the feast of trumpets or the first day of the new year, which fell together on that day; the calends, or first day of the month, was with the Heathens sacred to deity ^F19, in imitation of the Jews:

and I should not fail to sit with the king at meat;
it had been usual for him at such a time to sit at table with the king; next to him, as Jarchi interprets it, either as his son-in-law, or as one of his princes; the custom being for the king, and his family and nobles, to eat together on that day upon the peace offerings; and it was the duty of David to attend at that time, and it might be expected he would:

but let me go;
he asked [leave] of Jonathan, who had power in his father's absence to grant it, he not being yet returned from Naioth:

that I may hide myself in the fields, unto the third [day] at even;
or until the time of the evening of the third day, as the Targum, which was the evening of the second day of the month; for that was the third from that evening they were discoursing together, as Ben Gersom observes; the fields he proposed to hide himself in were near to Gibeah, and he doubtless meant some cave in those fields, where he might be, and not be seen by men; though it cannot be thought that he remained, or proposed to remain, in such a place during that time, where he would be in want of food, but that he would abide incognito among his friends somewhere or another, until the festival was over.