The original Chinese Goang
Wuzu said, "For instance, a water buffalo (bull ox) passes through the window lattice;
the head, horns, and four hoofs all pass through completely. What is the reason why the tail cannot pass through?”
Traditional Commentaries and .... Poems (Gata)
If anyone can open one eye at this point and say a word of Zen, he is qualified to repay the four gratifications,
and, not only that, he can save all sentient beings under him.
But if he cannot say such a word of true Zen, he should turn back to his tail.
If within you invert, are able to manifest one single eye, and are able to issue one turning word,
you can rise up to declare the four loving-kindnesses and descend to give aid in the three realms of existence.
Maybe you are not yet like that? Then you still must look after and attend to the tail to be able to begin.