It is trendy to be against saying “Because I said so” to your children. You don’t want to come across as wielding arbitrary authority.
You don’t want them to blindly accept authority.
You don’t want to raise peons.
But authority is built into the world. It’s how God made it, starting from Him and flowing down to kings, magistrates, church elders, and fathers. We should always act as if there is someone in authority over us…because there is.
You don’t teach your children to blindly obey authority, but to obey it because God is in heaven and God has instituted it.
Your children absolutely should accept “Because I am your father” as a reason to do something or not do something. Do not lean on it all the time. It should be rare. And the context of this statement should come out of an environment of love.
But they should obey you because you are their father. Even if they disagree with you. Especially if they disagree with you.
When God gave the Law to Israel, he said
I am the Lord your God, who brought you out of the land of Egypt, out of the house of slavery.Exodus 20:2
This was the main reason. Any other reasons the Israelites should obey flowed out from this main reason.
“I am the Lord your God.”
Your children will live under authority their entire lives. That authority will be wielded imperfectly, just like their father’s. Give them some practice in dealing with that fact of life.
Most of the time, you should give them an explanation. This builds trust. Explain to them why it is better this way and answer their questions with patience.
God himself gives reasoning for the fifth commandment, perhaps because He well understood human nature. He knows we are but dust.
“Honor your father and your mother, that your days may be long in the land that the Lord your God is giving you.”Exodus 20:12
“Because I said so” is a big check to write. You fill the account with love and trust, so make lots of deposits.
But do not let anyone shame you for saying it. They are projecting their own insecurities and bitterness against authority.
You are their father. God has invested you with responsibility and with the authority to manage that responsibility. Do it with wisdom.
And when your children hear “Because I said so” or “Because I am your father,” they will not hear the impotent raving of a tyrant. They will hear the voice of one they implicitly trust.