This is basically a social-media health post using a catchy claim to encourage engagement.
Simple meaning
“They call it natural morphine because it removes muscle, joint, rheumatic pain” means the post is claiming that a particular natural ingredient or recipe can provide strong pain relief for muscles, joints, and rheumatic pain.
“Natural morphine” is not a medical term and does not mean the remedy actually works like morphine. Such claims need scientific evidence.
The second part:
“To keep getting my recipes, you just have to say… Thank you!”
is simply an engagement request. The person is asking readers to comment “Thank you!” so they can continue receiving or seeing the recipes.
In short: it combines an unproven health claim with a request for comments/engagement.
