Our family hath a sacrifice in the city; and my brother, he hath commanded me. — Jonathan answers the king’s question in the way previously agreed upon between him and David. He quotes the excuse in David’s own words.
The LXX., instead of “my brother,” has “my brothers.” It thus alters the original, not understanding the singular “brother,” Jesse, their father, being still alive. The brothers collectively might, the LXX. seemed to think, have bidden David to the family sacrificial feast. Dean Payne Smith suggests that as the ceremony was not a private family gathering, but one shared in by the district, the “brother” (probably the eldest), likely enough, was the convener of the absent member of the house of Jesse.