1/19 Mark 1:45
45 But he went out and began to talk freely about it, and to spread the news, so that Jesus could no longer openly enter a town, but was out in desolate places, and people were coming to him from every quarter.
A leper came to Jesus and pleaded with Jesus to be made clean. The leper said that he knew that if Jesus was willing, Jesus could do it. Jesus touched him. People knew that touching a leper made a person unclean and that the person would require a cleansing ritual. But Jesus said, "I will; be clean." The leper instantly showed no signs of leprosy. Jesus sternly charged the man, "See that you say nothing to anyone, but go, show yourself to the priest and offer for your cleansing what Moses commanded, for a proof to them." (See Leviticus 13 if you'd like a detailed description of the treatments Moses described.) Jesus' command tells us that Jesus observed the Laws of Moses and expected other Jews in His day to do so as well.
The man went out and began to tell everyone about the miracle. You can hardly blame him. Who knows how long he had been isolated from people because of the affliction. Anyone would be so excited that it would be hard to keep it in. Yet the consequences for Jesus were constant distractions and interruptions. Talking about good things is not always a good thing.
Perhaps you have had the experience of the Holy Spirit sternly charging you not to tell anyone about a certain thing. Did it burn inside you? Did you obey? We don't always see or understand the consequences of disobedience. If there are times we should not speak of good things, how much more of evil done to us? The last member of our body to be tamed is the tongue (James 3:8). The more we practice obeying that still, small voice, the easier it becomes to stifle the desires of our old nature.
Consider: When you discern the Holy Spirit telling you not to speak of a matter, remember that the consequences of disobedience can be much more than you would think.