When someone will go and say a consequence for someone's actions, sometimes making it sound realistic sometimes not so much, but none the less there is no intention on following up with those consequences.
"I swear I will leave you Henry after 15 years of marriage if you don't stop drinking"
"yea right, you and your empty threats"
When someone threatens you with an imaginary godly punishment.
1: god will send you to hell for your heathen ways.
2: that ain't nothing but empty threat from a finger gun. Get out here!