The application required one to draw his opponent towards himself.
The student had doubts about drawing an opponent in. After all, isn't that putting oneself into danger instead?
Well, you can't hit someone if he is out of your reach. And if he is within your reach, you are within his too. It is this psychological barrier that one must learn to overcome in order to be able to apply taiji.
Being within his reach does not mean you are in danger. You need to put him within your own reach, yet in a way either to expose him, or to make sure he is unable to hit you (that is to say, neutralise him). So while he may be close, he is the one in danger, not you.
So don't be afraid to draw your opponent in. Instead, know what is the danger, and how you are going to deal with it.