肇論新疏 3.172

3.172

八極，八方之極際也。無心之心，遍知一切而何勞；非身之身，分應八方而弗患。至于遣侍問候，只敘禮儀；答以輕安，俯隨世範。豈曰小疾須乳，為雷居士呵哉？後二句，以身心無為，故非所損益。初句，擬《繫辭》。

'Eight extremities' refers to the utmost reaches of the eight directions. The mindless mind knows all things universally, so how could there be toil? The non-bodily body divides to respond to the eight directions, so he suffers no distress. As for sending an attendant to inquire after health, that is merely to observe social etiquette; answering that he is light and at ease merely complies with worldly standards. How could one say that, having a slight illness, he required milk, and was rebuked by the lay devotee Lei? The latter two lines mean that because body and mind are unconditioned, they are not subject to loss or gain. The first line emulates the Appended Remarks [of the Yijing].