Matthew 9:30

And their eyes were opened. And Jesus sternly warned them, saying, "See that no one knows it."

Surrounding context

9:29 Then He touched their eyes, saying, "According to your faith let it be to you."

9:30 And their eyes were opened. And Jesus sternly warned them, saying, "See that no one knows it."

9:31 But when they had departed, they spread the news about Him in all that country.