The Gateless Gate, by Ekai, called Mu-mon, tr. Nyogen Senzaki and Paul Reps , at sacred-texts.com
Basho said to his disciple: "When you have a staff, I will give it to you. If you have no staff, I will take it away from you."
Mumon's comment: When there is no bridge over the creek the staff will help me. When I return home on a moonless night the staff will accompany me. But if you call this a staff, you will enter hell like an arrow.