1 Samuel 20:6
If thy father at all miss me, then say, David earnestly asked leave of me that he might run to Beth-lehem his city: for there is a yearly sacrifice there for all the family. If thy father at all miss me, then say, David earnestly asked leave of me that he might run to Beth-lehem his city: for there is a yearly sacrifice there for all the family.
The verse comes from the time after David slew Goliath when Saul kept David with him and would not let him return to his father's house. It belongs to the account of Jonathan's sacred bond with David, in which the soul of Jonathan was knit with the soul of David and Jonathan loved him as his own soul, they were united as brethren by covenant, and Jonathan gave to David his robe and his garments even to his sword and to his bow and to his girdle. In that setting David was entrusted with important responsibilities, in which he preserved his modesty and won the affection of the people and of the royal household. God used Jonathan to preserve David's life when Saul tried to kill him. David's hardships in this period helped prepare him to rule and taught him to trust fully in God.
David and Jonathan agreed on the excuse in the verse to explain David's absence from Saul's table as a test of whether Saul intended to kill David. The test centered on the new moon, a sacred festival in Israel held the day after their interview, at which both young men were expected at the king's table but David feared to be present. The plan was for David to visit his brothers in Bethlehem for his father's household sacrifice and then hide three days in a field not far from the banqueting hall while Jonathan noted the effect on Saul. If inquiry was made about the whereabouts of the son of Jesse, Jonathan was to say David had earnestly asked leave to go home to attend the family sacrifice. A favorable response would mean David could safely return to court, but rage over his absence would decide that David must flee.