Tea is the ordinary matter like dressing and eating each one needs and use. As Buddha dharma that all monastics have Buddhist nature, no high and low, saints and mortals equal and each one can enlighten it. Chan and tea are common while human and Buddha are interlinked. 

Buddha and dharma are is visible at any time and Chan ceremony can be entered at any moment. As long as people have the heart, be able to enlighten. How to enlighten? Go for tea! (From Words of Chan by Shi Yongxin)