Dogen instructed,

Do not make arrangements in advance for obtaining food and clothing. Only when you run out of food and have nothing to cook, should you beg for food. Even planning ahead regarding who to ask for what you need is the same as storing food. This is evil food gained by improper means.  

A Zen monk should be like a cloud with no fixed abode, like flowing water with nothing to rely on. Such is called a monk.  

Though possessing nothing except robes and a bowl, if you rely on some patron or close relative, you and they are both bound to each other, so the food becomes impure. It is impossible to realize the pure and great dharma of the buddhas with a body and mind fed and maintained by impure food. Just as cloth dyed with indigo becomes indigo-blue, and cloth dyed with the Chinese cork tree becomes yellow, a body and mind dyed with food gained by improper means becomes a body of impure-life. Desiring to attain the buddha-dharma with such a body and mind is like pressing sand to get oil.  

Just handle everything in accordance with the Way in each situation. To plan in advance goes entirely against the Way. You should consider this very carefully. (Shōbōgenzō Zuimonki, Book 5, Chapter 21)