金剛經纂要刊定記 3.34

3.34

如常敷座等者。謂如來每會說般若，皆自敷座具，為般若出生諸佛即是佛母，表敬般若，故自敷座。已說八會，此當第九，儀軌不易故曰如常。趺謂足背，加謂以一足壓一足，結即兩足不散表吉祥。故《智論》云：「見畫加趺坐，魔王尚驚懼，何況入道人，端身不傾動。」又為正觀五種因緣，是故結加趺坐。一、由身攝歛速發輕安，最為勝故。二、由此宴坐能經時久，不令身速疲極故。三、由此宴坐是不共法，外道他論皆無有故。四、由此宴坐形相端嚴，令他見已極敬信故。五、由此宴坐佛佛弟子共所開許，一切賢聖所稱讚故。正觀五種因緣，是故應當結加趺坐。

"Spreading his seat as usual" means that in every assembly where the Tathāgata expounded prajñā, he always spread the sitting mat himself; because prajñā gives birth to all buddhas and is thus the mother of buddhas, to express reverence for prajñā, he spread the seat himself. Having already expounded eight assemblies, this corresponds to the ninth; since the decorum and standard do not change, it is said to be "as usual." Fu refers to the instep of the foot; jia refers to placing one foot upon the other; jie means the two feet do not scatter, symbolizing auspiciousness. Therefore, the *Mahāprajñāpāramitōpadeśa* says: "Seeing even a painting of the cross-legged sitting posture, / The Māra King is already terrified; / How much more so for a person who enters the Way, / Keeping the body upright without swaying!" Furthermore, for the sake of five causes and conditions of correct contemplation, one sits cross-legged: First, because through drawing in and collecting the body, light ease quickly arises, which is most supreme. Second, because through this quiet sitting one can endure for a long time without causing the body to tire quickly. Third, because this quiet sitting is an uncommon Dharma, entirely absent from non-Buddhist other doctrines. Fourth, because this quiet sitting presents a dignified and majestic appearance, causing others upon seeing it to feel utmost reverence and faith. Fifth, because this quiet sitting is mutually permitted by all buddhas and disciples of buddhas, and praised by all worthies and nobles. For the sake of these five causes and conditions of correct contemplation, one should sit cross-legged.