Jesse said to David his son, “Now take for your brothers an ephah of this parched grain and these ten loaves, and carry them quickly to the camp to your brothers; 18 and bring these ten cheeses to the captain of their thousand; and see how your brothers are doing, and bring back news.” 19 Now Saul, and they, and all the men of Israel were in the valley of Elah, fighting with the Philistines.
20 David rose up early in the morning and left the sheep with a keeper, and took the provisions and went, as Jesse had commanded him.
1 Samuel 17:17-20 (WEB)
This biblical example is referring to King David's obedience to his father. This act of obedience led King David to the battlefront where he received his renowned victory over Goliath. At that time, Israel was battling with the Philistines and King Saul reigned over Israel. King David had not yet taken the throne but he was already anointed King by YHWH through the prophet Samuel.