but David went back and forth from Saul to tend his father's sheep in Bethlehem.

1 Samuel 16:11
And Samuel asked him, "Are these all the sons you have?" "There is still the youngest," Jesse replied, "but he is tending the sheep." "Send for him," Samuel replied. "For we will not sit down to eat until he arrives."

1 Samuel 16:19
So Saul sent messengers to Jesse and said, "Send me your son David, who is with the sheep."

1 Samuel 16:21
When David came to Saul and entered his service, Saul admired him greatly, and David became his armor-bearer.

1 Samuel 17:16
For forty days the Philistine came forward every morning and evening to take his stand.

1 Samuel 18:2
And from that day Saul kept David with him and did not let him return to his father's house.

But David went and returned from Saul to feed his father's sheep at Bethlehem.