This calligraphy entitled Silence-Thunder is by Rev Dr Sōyū Matsuoka Rōshi (1912-1997), the Dharma grandfather of the Southwind Sangha. The original is at the Atlanta Sōtō Zen Center.
Silence-Thunder evokes the essence of our Zen practice:
…Yaoshan had not gone up to the hall [to give a talk] for some time. The director said, “For a while the great assembly has been missing the master’s kind instruction.”
Yaoshan said, “Strike the bell.” The bell was sounded and the assembly gathered. Yaoshan ascended the seat. After a while he simply descended from the seat, and returned to the abbot’s quarters.
The director followed after him and said, “Master, you agreed before to expound the Dharma for the assembly. Why didn’t you offer us a single word?”
Yaoshin said, “There are sutra teachers for sutras, and commentary teachers for commentaries. Why do you blame this old monk?”
The teacher Dōgen said: Do you want to understand “There are sutra teachers for sutras, and commentary teachers for commentaries. Why do you blame this old monk?”
Why are you criticizing? This old monk is the teacher, and you are the disciple.
Do you want to understand “Master, you agreed before to expound the Dharma for the assembly. Why didn’t you offer us a single word?”
The sound of thunder shakes in the distance. Therefore [the director] said that [Yaoshin] did not offer a single word.
From Dōgen’s extensive record: a translation of the Eihei Kōroku, translated by Taigen Dan Leighton and Shohaku Okumura, Somerville, MA: Wisdom Publications, 2004, p. 440. Used by permission of Wisdom Publications.