金剛經纂要刊定記 3.174

3.174

從座起者。師資之道尊卑頗殊，欲有諮詢不可坐問，此同曾子避席對夫子也。《孝經》中夫子問曾子曰：「先王有至德要道以順天下，民用和穆上下無怨。汝知之乎？」曾子避席曰：「參不敏，何足以知之？」雖彼答此問，而致敬是同也。偏袒右肩，是彼方儀則，此土非儀也。欲問如來故須偏袒。

On "rising from his seat": the way between teacher and disciple has a considerable difference between the exalted and the lowly; wishing to make an inquiry, one cannot remain seated to ask. This is like Zengzi leaving his mat to reply to the Master. In the Classic of Filial Piety, the Master asked Zengzi, saying: "The former kings possessed supreme virtue and essential Dao to keep the world in accord, whereby the people lived in harmony and high and low harbored no resentment. Do you know it?" Zengzi left his mat and said: "Shen is not clever; how could he be sufficient to know it?" Although that was an answer and this is a question, the rendering of respect is the same. Baring the right shoulder was the ritual deportment of that region, not the decorum of this land. Wishing to question the Tathāgata, he thus had to bare his shoulder.