वेदान्त पारिजात सौरभ (भगवद् निम्बार्काचार्य - द्वैताद्वैत वेदान्त ब्रह्मसूत्र भाष्य सटीक)

746 VEDĀNTA-KAUSTUBHA [SŪ. 3 4. 28.
ADH. 7.]
Vedānta-kaustubha
It has been stated that calmness and the rest are subsidiary
parts of knowledge. Now, wishing to dispose of the objection, viz.
like that, the eating of all food, too, is a subsidiary part of knowledge,—
the author points out that such eating relates only to cases of life
being in danger.
In the Bṛhadāraṇyaka, it is said "Verily, what is not food is
not taken by him" (Bṛh 6.1.14); as well as in the Chāndogya · "Verily,
to one who knows thus, there is nothing whatever that is not food"
(Chānd 5.2.1) Here the doubt is, viz, whether this eating of all food
by one who knows the vital-breath is valid, as a subsidiary part of
the doctrine of the vital-breath, like calmness and so on, even when
one is in a healthy state; or only in the event of danger to life. What
is reasonable? If it be suggested: when one is in a healthy state,—
we reply: only "in the event of danger to life", there is "permission
of all food". Why? "On account of that being seen," i e because
in the text: "When the Kurus were destroyed by hail-storm ¹"
(Chānd. 1.10 1), the eating of improper food is found to be allowable
only in the event of life being in danger. When all food being eaten
up by a kind of animals called 'maṭacī' there came to be a famine
among the Kurus, then the sage Cākrāyaṇa, seized with hunger, ate
the leavings of an elephant-keeper ². From this it is known that the
eating of all food is permitted even to one who knows the vital-breath
only in the event of danger to life.
COMPARISON
Baladeva
Interpretation same, but he takes this adhikaraṇa as concerned
specially with the pariniṣṭha devotee.
¹ Śrīnivāsa, however, understands the word as a kind of crop-destroying
animals. See below.

• Vide Chānd. 1.10.1–5 for the story. The sage ate the leavings because
  he would have died without food, but refused to drink leavings because he could
  survive without drink.