I Samuel 16:3-6

Then invite Jesse to the sacrifice, and I will show you what you shall do; you shall anoint for Me the one I name to you.” So Samuel did what the LORD said, and went to Bethlehem. And the elders of the town trembled at his coming, and said, “Do you come peaceably?” And he said, “Peaceably; I have come to sacrifice to the LORD. Sanctify yourselves, and come with me to the sacrifice.” Then he consecrated Jesse and his sons, and invited them to the sacrifice. So it was, when they came, that he looked at Eliab and said, “Surely the LORD’s anointed is before Him!”