According to Your Dictionary, "Clauses are units of grammar that contain a predicate (verb) and a subject (noun)."
Genesis 1:1, the first verse of the Bible, reads, "In the beginning God created the heavens and the earth." "In the beginning" is an adjectival prepositional phrase. It describes when the action occurred. "God created the heavens and the earth" is the first clause.
So, grammatically/biblically speaking, yes!
This begs the question, is God the first Claus? Maybe? He does give good gifts (Matthew 7:11) and the most important was certainly given on Christmas.
Is God the first Klaus? "Klaus" means "victory of the people." Kind of. Jesus is God, and He is our victory against sin and death.
Is God the first claws? Jesus is described with blazing eyes, glowing bronze feet, and a sword coming out of His mouth (Revelation 1:14-16), but I don't recall any passage describing God with claws. You may be thinking of the scene in
The Voyage of the Dawn Treader when Aslan rips the dragon skin off Eustace.
Is God the first legal clause? According to Dictionary.com, a legal clause is "a distinct article or provision in a contract, treaty, will, or other formal or legal written document." Was God the first legal clause in Scripture? Not really. The first legal clause may be from Genesis 1:28: "Be fruitful and increase in number; fill the earth and subdue it. Rule over the fish in the sea and the birds in the sky and over every living creature that moves on the ground." This is when God set up the legal terms of Adam and Eve's responsibility for their governance of God's creation. God as clause is found later in the Bible. It's inferred with Abraham, but specific in Jeremiah 32:38 when, speaking about Israel, He promises, "They will be my people, and I will be their God."
But we can say that God is often the initiator of legal clauses, including the one with Adam and Eve. That makes Him the
first cause of the first clause.