C. F. Keil and Franz Delitzsch on 1 Samuel 20:27-29

1Sa 20:27-29

But on the second day, the day after the new moon (lit., the morrow after the new moon, the second day: השּׁני is a nominative, and to be joined to ויהי, and not a genitive belonging to החדשׁ), when David was absent from table again, Saul said to Jonathan, “Why is the son of Jesse not come to meat, neither yesterday nor to-day?” Whereupon Jonathan answered, as arranged with David (compare 1Sa 20:28 and 1Sa 20:29 with 1Sa 20:6). “And my brother, he hath commanded me,” i.e., ordered me to come. צוּה as in Exo 6:13, and אחי, the elder brother, who was then at the head of the family, and arranged the sacrificial meal.