It is often used in situations like:
* When someone is leaving: "Chosumnida! (Take care!)"
* When someone is going somewhere potentially dangerous: "Chosumnida! (Be careful!)"
* When expressing general concern for someone's well-being: "Chosumnida! (Take care of yourself!)"
The use of "chosumnida" implies a level of respect and consideration for the person you are addressing.