1 Samuel 17:14-17 New International Version (NIV)

14. David was the youngest. The three oldest followed Saul,

15. but David went back and forth from Saul to tend his father’s sheep at Bethlehem.

16. For forty days the Philistine came forward every morning and evening and took his stand.

17. Now Jesse said to his son David, “Take this ephah of roasted grain and these ten loaves of bread for your brothers and hurry to their camp.

1 Samuel 17