Who is this King of glory? The Lord of hosts, he is the King of glory. Selah
This short psalm was likely sung as a processional hymn while entering the tabernacle, perhaps while bearing the Ark of the Covenant. You can hear the jubilance in the voices of the people as they respond to the question, “The Lord of hosts, he is the King of glory.”
While this may have that historical context, we can substitute the entering into the tabernacle with God entering our hearts. We remember with gladness the day we accepted Christ as our King, and our lives forever changed. Through the Holy Spirit, we became new people through the water and the blood. Every time we come into God’s presence, acknowledging his grace, we re-experience that first time. It is easy for us to answer with the same enthusiasm as the people entering the sanctuary, our Triune God, Father, Son, and Holy Spirit our Lord and King.
Lord of hosts, King of glory, we give you praise today. We rejoice and give thanks for your presence within us. We acknowledge you are our God, and there is no other like you. You are our Creator. Redeemer and Sustainer -- all we need can be found in you. Heavenly Father, we ask that you be with us this day and that we do your will in all things. In the name of your Son, Christ Jesus, we pray. Amen.
The term Selah is somewhat of a mystery. However, the most likely explanation is it serves as a musical notation of some kind. You will often see it used in the Psalms.