1 Samuel 20:25

And the king sat upon his seat, as at other times, even upon a seat by the wall: and Jonathan arose, and Abner sat by Saul’s side, and David’s place was empty.

The empty seat belongs to the time after the slaying of Goliath, when Saul kept David with him and would not permit him to return to his father's house. Then the soul of Jonathan was knit with the soul of David, and Jonathan loved him as his own soul, their hearts being knit together in a sacred bond of union. Jonathan and David made a covenant to be united as brethren, and Jonathan gave David his robe and his garments, even to his sword and to his bow and to his girdle.

At the same time David was entrusted with important responsibilities, yet he preserved his modesty and won the affection of the people as well as of the royal household. The vacant place was seen on the second day of the new-moon sacred festival at the king's table in the banqueting hall, when David's continued absence was noticed. Both David and Jonathan were expected there, but David feared to be present and by agreement with Jonathan went toward Bethlehem and then hid in a field near the hall to test Saul's feeling by three days' absence.

On the first day of the feast no inquiry was made about David, but when his place was vacant the second day Saul asked why the son of Jesse had not come to meat. Jonathan's answer about the family sacrifice drew Saul's ungovernable anger and demand for David's death, which decided the matter of David's flight. The bond between Jonathan and David remained unbroken till the death of Saul and Jonathan, and this was the Lord's doing so that Jonathan might be the means of preserving David's life when Saul would try to kill him.

God's providence connected David with Saul so that by wise behavior David might obtain the confidence of the people. By a long course of hardships and vicissitudes he was thus led to put entire trust in God while being prepared to become ruler of His people.