'Sternly' in the Bible

And their eyes were opened. Then Jesus sternly warned them, "See that no one knows about this."

But he sternly warned them not to make him known.

But he sternly ordered them not to make him known.

But some itinerant Jewish exorcists tried to invoke the name of the Lord Jesus over those who were possessed by evil spirits, saying, "I sternly warn you by Jesus whom Paul preaches."