You mean never sell or trade a gun? Is that the one?
Shoot, I buy, sell, trade, and swap them all the time. They're just things, meant to be bought and sold. I don't get emotionally attached to them.
For God so loved the world, that He gave His only begotten Son, that whoever believes in Him should not perish, but have everlasting life.
John 3:16 (NKJV)