"Tathagata" means "thus come" or "thus gone."
Thus come and thus gone, but actually neither come nor gone. Boundless, and yet omnipresent. Immeasurable, so how could it be illustrated? Even though impossible to fathom its depth and width, in order to let sentient beings all realize that they were originally thus come, and no longer remain lost in the transmigration of births and deaths, it does not hurt to skillfully set up terminology—to distinguish "Buddha" from "sentient beings"—so as to lead the ignorant and deluded multitude toward enlightenment.
Once the state of Buddhahood had been established, its meritorious qualities of five wisdoms, four compassions, six supernatural abilities, and eighteen transcendental qualities, etc., must be explicated in details to illustrate the superiority of perfect enlightenment so that all beings would look up to it and aspire to attain it. Also, so that beings would be able to discern its distinction from and transcendence to other teachings.
Having practiced in accordance with the Dharma for long, one would receive inspirational blessings from Buddhas now and then, and hence naturally born from one's heart praises of respect and gratitude. In praising Buddhas one merely expresses one's true feelings of admiration and gratitude, and yet such praises could move others to developing faith and admiration, and hence yield functions of conversion.
Words and expressions are quite limited, and yet meritorious virtues of Buddhas could not be exhaustively praised. To illustrate Buddhas' virtues to beings in the worldly realms, no better way than to personally carry out Buddha's deeds by following his path step by step. Thus, even if one remained silent, the resulting illustration of Dharma path would supersede constant praising in words.
All phenomena in the Dharmadhatu, including all sorts of sounds and silence, are nothing but thus come and thus gone. When thus comprehended all are nothing but appearances of Tathagata. Without waiting for our aspiration to sing in praising, endless and immeasurable praising and illustration of Tathagata are incessantly and perpetually on display.
Written in Chinese and translated on April 14, 2009