Memoranda of the Words of Rikyu (1691)
Book One: Oboegaki Once, when Rikyu had been speaking of chanoyu at Shuun-an, I asked," You often remark that, although chanoyu has its roots in [the formal tea employing] the daisu, when considering the deepest attainment of its spirit, nothing surpasses the informal tea held in a small room. Why should this be so?" Rikyu responded: "Chanoyu of the small room is above all a matter of performing practice and attaining realization in accord with the Buddhist path. To delight in the refined splendor of a dwelling or the taste of delicacies belongs to worldly life. There is shelter enough when the roof does not leak, food enough when it staves off hunger. This is the Buddhist teaching and the fundamental meaning of chanoyu.
Also No. 20: The meal for a gathering in a small room should be but a single soup and two or three dishes; sake should also be served in moderation. Elaborate preparation of food for the wabi gathering is inappropriate. Needless to say, harmonizing strongly and lightly flavored dishes should be understood in the same way as that of the thick and thin services of tea.
And #21: The handai 飯台 First the host carries the handai in and wipes it clean with a cloth. He then puts the shaped rice in rice bowls, covers them, and places them on top of soup bowls. In this manner he lines up on a tray as many services as there are guests, carries them in, and raises them to the handai. The soup he serves from a soup pitcher.