Zen koan of the day - What is it?

What is it?

When Hsueh Feng was living in a hut, there were two monks who came to pay their respects.
Seeing them coming, he pushed open the door of the hut with his hand, popped out, and said, "What is it?"
A monk also said, "What is it?"
Feng lowered his head and went back inside the hut.
∫
Later the monk came to Yen T'ou.
T'ou asked, "Where are you coming from?"
The monk said, "I've come from Ling Nan."
T'ou said, "Did you ever go to Hsueh Feng?"The monk said, "I went there."
∫
T'ou said, "What did he have to say?"
The monk recounted the preceding story.
T'ou said, "What did he say?"
The monk said, "He said nothing; he lowered his head and went back inside the hut."
T'ou said, "Alas! It's too bad I didn't tell him the last word before; if I had told him, no one on earth could cope with old Hsueh."
∫
At the end of the summer the monk again brought up the preceding story to ask for instruction.
T'ou said, "Why didn't you ask earlier?"
The monk said, "I didn't dare to be casual."
T'ou said, "Though Hsueh Feng is born of the same lineage as me, he doesn't die in the same lineage as me.
If you want to know the last word, this is it."

dcj commentary: Seize the moment.