O Lord is the second of the O Antiphons, a traditional prayer of many centuries duration. Of course, "Lord" or "Adonai" is used throughout the Old Testament and is not in any way unique to Isaiah. But the reference used in Isaiah in conjunction with this antiphon is 33:22. "For the Lord is our judge, the Lord is our lawgiver, the Lord is our King; it is he who will save us."
Like much of Isaiah the verse looks both backward and forward. God gave the law on Mount Sinai; he was King of Israel; he saved them from Pharaoh and slavery in the Exodus and continued to save them from their enemies. Looking forward from Isaiah, Jesus gave a fuller interpretation of the law (Matthew 5); he is King of Kings and will return to judge; he saved us from slavery to our sins.
For reflection: Let us, again, use the verse from Isaiah as a starting point of praise to our God.
Let us pray. O Lord, you are our just judge and righteous lawgiver, you are our King, you are the one who saves us.
I started this website and blog on May 1, 2012. I am a Catholic who has been in ministry for many years. I first developed what I would call a close relationship with Jesus in the early 1970s. Ever since then I have been praying with people for healing and other needs. It is because I have seen so many of these prayers answered that I am so bold as to offer to pray for you individually through this website and phone line.