What’s an appropriate consequence when your child bullies others?

I know it's really early and I have plenty of time to raise him to be nice, but today at daycare, my 3 year old son pushed a kid off of a bike he wanted to ride.

My only punishment was to put him in time out.

That made me realize, I don't know what I'll do to punish him as he gets older of he's still bullying other children.

When I was a kid, I only bullied once and my dad took me out to his farm and made me pickup rocks, big and small, out of his field for 8 hours. I never even thought to bully another kid after that.

I don't have a farm or anything that can be as good of punishment as that was.
What’s an appropriate consequence when your child bullies others?
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