In his work "Chanoyu Ichie Shu" (Collection on the Oneness of Chanoyu), there is a famous "Ichigo Ichie" (a preaching of Sado dictating that each occasion on which hospitality is offered and received is to be cherished as a unique experience in one's life).
著書『茶湯一会集』巻頭には有名な「一期一会」がある。