The priests were mediators of God’s covenant with Israel. A mediator is someone who stands between two parties to represent them. The priests stood between God and the people.
Their duty was to pray for the people. They also spoke God’s blessing over them. In this way, they helped maintain the covenant relationship between God and Israel (see Romans 8:34; Hebrews 2:17–18; 4:14–16). He intercedes for believers, which means he prays for them before God. As the great high priest, he brings his people into God’s presence and secures God’s blessing for them.