The reference to “high and low” places is from this Koan concerning

GuishanLingyou (771-853) and his disciple Yangshan Huiji (807-883). The dialogue reads:

 

    One day [Yangshan] went along with Guishanto prepare a field for planting. The teacher [Yangshan] asked, “Why is it that this partis low and that part is high?” Guishan said, “Water can level things;let us just use water to level it.” The teacher said, “Water is notreliable, master. It is just that high places are high and level; low placesare low and level.”

Guishan assented.

Keep the white waterwith which you have washed the rice; do not wastefully discard it. In ancienttimes they used a cloth bag to strain the white water and used it to boil therice when making gruel. Having put [the rice] into the cooking pot, pay attentionand guard it. Do not allow mice and the like to touch it by mistake, nor anycovetous idlers to examine or touch it.

When cooking thevegetable side dishes for the morning gruel, also prepare the platters and tubsused for rice, soup, etc., as well as the various utensils and supplies thatwill be used for that day's midday meal. Wash them so that they are completelypure and clean, placing up high those that belong in high places and puttingdown low those that belong in low places. "High places are high and level;low places are low and level." Treat utensils such as tongs and ladles,and all other implements and ingredients, with equal respect; handle all thingswith sincerity, picking them up and putting them down with courtesy.

From: Tenzo Kyokun - Instructions for the Cook by Eihei Dogen - Translated by Griffith Foulk