Know that to give to yourself is a part of giving. - Dōgen

When even for a moment you sit upright in samadhi expressing the buddha mudra [form] in the three activities [body, speech, and thought], the whole world of phenomena becomes the buddha mudra and the entire sky turns into enlightenment. At this moment, all things actualize true awakening; myriad objects partake of the buddha body; and sitting upright, a glorious one under the bodhi tree, you immediately leap beyond the boundary of awakening. Then you turn the unsurpassably great dharma wheel, and expound the profound wisdom, ultimate and unconditioned.

I was also told that the Eihei Daishingi (Regulations for Eiheiji Monastery), of which the Tenzo Kyōkun is the first chapter, was one of the easier works of Dōgen, since it deals with practical matters.

In general, when you are a beginner, you cannot fathom the buddha way. Your assumptions do not hit the mark. The fact that you cannot fathom the buddha way as a beginner means not that you lack ultimate understanding but that you do not recognize the deepest point.