The Gateless Gate, by Ekai, called Mu-mon, tr. Nyogen Senzaki and Paul Reps [1934], at sacred-texts.com
A traveling monk asked an old woman the road to Taizan, a popular temple supposed to give wisdom to the one who worships there. The old woman said: "Go straight ahead." When the monk proceeded a few steps, she said to herself: "He also is a common church-goer."
Someone told this incident to Joshu, who said: "Wait until I investigate." The next day he went and asked the same question, and the old woman gave the same answer.
Joshu remarked: "I have investigated that old woman."
Mumon's comment: The old woman understood how war is planned, but she did not know how spies sneak in behind her tent. Old Joshu played the spy's work and turned the tables on her, but he was not an able general. Both had their faults. Now I want to ask you: What was the point of Joshu's investigating the old woman?