大乘起信論廣釋卷第三．四．五 5.109

5.109

論。唯除坐時至不應作　釋曰。已顯觀相。此即第三結觀分齊。唯除修止端坐之時。若餘一切悉當觀察。順理應作違不應作。故新論言。行住坐臥常應觀察所可作等。

[Treatise:] Except only when sitting [in meditation and cultivating śamatha, at all other times they should constantly contemplate what ought to be done and what] ought not to be done.
[Commentary:] Having explained the characteristics of contemplation, this is the third part, which concludes the scope of contemplation. Except only during the time of upright sitting when cultivating śamatha, at all other times they should completely contemplate: that which accords with principle ought to be done; that which violates it ought not to be done. Thus the new treatise says: "In walking, standing, sitting, and lying down, they should constantly contemplate what can be done," and so forth.