Minecraft wiki entry for Things_to_do_when_bored, associated text: Command for Knockback Stick (and other enchantments)
/give @s stick{display:{Name:"\"Knockback Stick\""},Enchantments:[{id:sharpness,lvl:1000},{id:fire_aspect,lvl:10},{id:knockback,lvl:1000},{id:looting,lvl:1000}]}