The four-character idiom 和敬清寂 meaning "Four Virtues of Tea" as described by the 16th century Tea Master Sen Rikyuu consists of the kanji和 (read wa) meaning "Harmony", 敬 (read kei) meaning "Respect", 清 (read sei) meaning "Purity", and 寂 (read jaku) meaning "Tranquility".
This is a very popular phrase and this art makes an excellent gift especially for a Japanese Tea Ceremony enthusiast, Bonsai artist or Ikebana artist.