The new moon festival was a joyous occasion (Numbers 10:10). Celebrated once a month, it involved offering a burnt sacrifice to the Lord (Numbers 28:11) likely followed by some kind of feast.1 Since David was the king’s son-in-law, his attendance at such an occasion was expected.
5 David said to Jonathan, “Behold, tomorrow is the new moon, and I should not fail to sit at table with the king. But let me go, that I may hide myself in the field till the third day at evening.