Why is tofu used in 心急吃不了热豆腐？
After tofu is made ready to eat, it is very hot. And even the outer part of the tofu get cooled down, the inner part is still very hot. It someone tries to eat it in a hurry, he will be hurt by the high temperature inside.

Rice or beef or some others cannot keep the inner part at a high temperature while the outer part is cooled down.

PS. When you try to eat tofu, please be careful.

PS2. sorry for the English, feel free to correct me.