At level 70, Master Hight at the Peak of Serenity gives you the quest: Continue Your Training: Master Tsang.
Roll down to the training grounds and find Master Tsang, a male pandaren monk. He says "Not all problems can be solved with your fists. Sometimes you must center yourself and channel your energy towards a distant target. Bow to me and we shall begin." /Bow to him. He then says "First you must prove yourself against my assistants. Defeat them, and then you may face me." His assistants, placed on poles will then start throwing rocks at you. You should then use Crackling Jade Lightning to knock them off the pole and fight each of them. When they're all defeated Master Tsang says "He was weak, but I am stronger! I thought I sensed a disturbance. I see you have defeated my assistants. Now you may face me." and becomes active. Defeat him to complete the quest.
When you hand in the quest to Master Hight, you get Enlightenment again. This buff gives you 50 % more experience from quests and kills. You can also choose between two brown belts; one for healing and one for damage and tanking.
After handing in the quest, a daily quest becomes available: Practice Makes Perfect: Master Tsang. Enlightenment can stack two times, so the second quest will give an additional hour. Never do more than 2 quests at the same time though!
34 days to go!