What does 1 Samuel 16:3 mean?

The Lord is sending Samuel the prophet to Bethlehem; he is to anoint a new king over Israel to eventually replace King Saul. Samuel is afraid Saul will kill him if the king learns of the mission (1 Samuel 16:1–2). In response, God told Samuel to take a young heifer to Bethlehem to sacrifice as a peace offering. The prophet could tell anyone who asked, truthfully, that he was traveling in order to make this offering.

Now God tells Samuel to invite Jesse to the sacrifice and subsequent feast. God will show Samuel what to do and whom to anoint as king. In other words, he need not fear. He should simply go. God will provide the needed instructions at the appropriate time. This account echoes God's call to Abraham (Genesis 12:1). Samuel is simply to go, to invite Jesse, and to expect that God will reveal the details as needed.

We are often called to step out in faith without knowing every detail. Obedience to what we know is part of living out our faith in the Lord (Hebrews 11:6). Like Samuel, we can trust that God will provide what is needed in the right time (James 4:13–17; Hebrews 13:5–8). Jesus told His followers, "Therefore do not be anxious…seek first the kingdom of God and his righteousness, and all these things will be added to you…sufficient for the day is its own trouble" (Matthew 6:31–34)