अभ्रं भूत्वा मेघो भवति मेघो भूत्वा प्रवर्षति त इह व्रीहियवा ओषधिवनस्पतयस्तिलमाषा इति जायन्तेऽतो वै खलु दुर्निष्प्रपतरं यो यो ह्यन्नमत्ति यो रेतः सिञ्चति तद्भूय एव भवति ॥ ५.१०.६ ॥
In plain words
having become mist, it becomes cloud; having become cloud, it rains down. Then they are born here as rice and barley, as plants and trees, as sesame and beans. Hard indeed is it to come forth from that; for only if someone eats him as food and pours him forth as seed does he become that further thing.
The commentators
Chāndogyopaniṣadbhāṣyam· Leaf 7.113· bhāṣya
यत्तु कैश्चिदुच्यते— सर्वकर्माश्रयोपमर्देन प्रायेण कर्म- णां जन्मारम्भकत्वम् । तत्र कानिचित्कर्माप्यनारम्भक- त्वेनैव तिष्ठन्ति कानिचिज्जन्म आरभन्त इति नोप- पद्यते, मरणस्य सर्वकर्माभिव्यञ्जकत्वात्, स्वगोचराभिव्य- ञ्जकप्रदीपवदिति । तदसत्, सर्वस्य सर्वात्मकत्वाभ्युप- गमात्—न हि सर्वस्य सर्वात्मकत्वे देशकालनिमित्तावरुद्ध- त्वात्सर्वात्मनोपमर्दः कस्यचित्क्वचिदभिव्यक्तिर्वा सर्वात्मनोप- पद्यते, तथा कर्मणामपि साश्रयाणां भवेत्— यथा च पूर्वानुभूतमनुष्यमयूरमर्कटादिजन्माभिसंस्कृताः विरुद्धानेक- वासनाः मर्कटत्वप्रापकेन कर्मणा मर्कटजन्म आरभमाणेन नोपमृद्यन्ते—तथा कर्मण्यप्यन्यजन्मप्राप्तिनिमित्तानि नोपमृ- द्यन्त इति युक्तम् । यदि हि सर्वाः पूर्वजन्मानुभववासनाः उपमृद्येरन्, मर्कटजन्मनिमित्तेन कर्मणा मर्कटजन्मन्यारब्धे मर्कटस्य जातमात्रस्य मातुः शाखायाः शाखान्तरगमने मातुरुदरसंलग्नत्वादिकौशलं न प्राप्नोति, इह जन्मन्यनभ्य- स्तत्वात् । न च अतीतानन्तरजन्मनि मर्कटत्वमेव आसी- त्तस्येति शक्यं वक्तुम्, ‘तं विद्याकर्मणी समन्वारभेते पूर्व- प्रज्ञा च’ इति श्रुतेः । तस्माद्वासनावन्नाशेषकर्मोपमर्द इति शेषकर्मसंभवः । यत एवम्, तस्माच्छेषेणोपभुक्तकर्मणः रमिति तकार एको लुप्तो द्रष्टव्यः; व्रीहियवादिभावो दु- र्निष्प्रपतः, तस्मादपि दुर्निष्प्रपताद्रेतःसिग्देहसंबंधो दुर्निष्प्र- पततर इत्यर्थः; यस्मादूर्ध्वरेतोभिर्बालैः पुंस्त्वरहितैः स्थवि- रैर्वा भक्षिता अन्तराले शीर्यन्ते, अनेकत्वादन्नादानाम् । कदाचित्काकतालीयवृत्त्या रेतःसिग्भिर्भक्ष्यन्ते यदा, तदा रेतःसिग्भावं गतानां कर्मणो वृत्तिलाभः । कथम् ? यो यो हि अन्नमत्ति अनुशयिभिः संश्लिष्टं रेतःसिक्, यश्च रेतः सिञ्चति ऋतुकाले योषिति, तद्भूय एव तदाकृतिरेव भवति ; तदवयवाकृतिभूयस्त्वं भूय इत्युच्यते रेतोरूपेण योषितो गर्भाशयेऽन्तः प्रविष्टोऽनुशयी, रेतसो रेतःसिगाकृतिभावि- तत्त्वात् , ‘सर्वैभ्योऽङ्गेभ्यस्तेजः संभूतम्’ इति हि श्रुत्यन्त- रात् । अतो रेतःसिगाकृतिरेव भवतीत्यर्थः । तथा हि— पुरुषात्पुरुषो जायते गोर्गवाकृतिरेव न जात्यन्तराकृतिः, तस्माद्युक्तं तद्भूय एव भवतीति ॥
In plain words
Some argue that when the mind—the storehouse of all past actions—is dissolved, those actions generally lose their power to trigger a new birth. They claim that while some karmas remain dormant, others rise to initiate a new life, and that death itself acts like a lamp, illuminating and activating all latent impressions at once. But this view is incorrect. In the ultimate reality, everything is interconnected and shares a common essence. Because all things are bound by space, time, and causation, a total annihilation or sudden, absolute manifestation of any single impression is impossible. The same rule applies to karmas and the minds that hold them. Consider a newborn monkey: it possesses many conflicting impressions from its past lives as a human, a peacock, or other creatures. When the specific karma that triggers a monkey's birth begins to unfold, those other past impressions are not wiped out. If they were, a newborn monkey would not instinctively know how to cling to its mother's belly as she leaps from branch to branch, having had no chance to practice such a skill in this life. We cannot simply assume its immediate past life was also that of a monkey, for the Upanishads declare that a soul is accompanied into its next life by its knowledge, its actions, and its past wisdom. Therefore, just like these deep-seated impressions, our residual karma is never entirely destroyed; it remains as a latent potential. This is why, when the major karma of a past life is exhausted, the soul descends through the rain into plants like rice and barley. Escaping this plant state is incredibly difficult, but finding a connection with a father's body is harder still. If the plant is eaten by children, celibates, or the elderly who cannot procreate, the descending soul is simply digested and lost. Only by rare coincidence, like a fruit falling from a tree as a crow lands on it, is the food consumed by a fertile man. When this happens, the latent karma of the soul finds its path to expression. The food becomes semen, which is the vital essence gathered from every limb of the father's body, already carrying his physical likeness. When this seed is sown in the womb during the fertile season, the soul takes on that very human form. Just as a human begets a human and a cow begets a calf, never a different species, the soul naturally assumes the likeness of the parent who gave it passage.
Close to the Sanskrit
But what is said by some—that through the destruction of the substratum of all actions, actions generally initiate birth; and in that case, some actions remain in a non-initiating state while others initiate birth—is not logical, because death is the manifester of all actions, like a lamp that manifests its own objects. That is false, because we accept that everything is of the nature of all. Indeed, when everything is of the nature of all, the complete destruction of anything anywhere, or its complete manifestation, is not logical, because of being restricted by space, time, and cause. So it must be for actions along with their supports. And just as those who are conditioned by previously experienced births as humans, peacocks, monkeys, etc., and who possess many mutually opposing impressions, are not destroyed when a monkey-birth is initiated by the karma that causes monkey-birth—so also in the case of karma, those which are the causes for obtaining other births are not destroyed; this is logical. If indeed all impressions of past births were destroyed, then when a monkey-birth is initiated by the karma that causes monkey-birth, a newborn monkey would not possess the skill of clinging to its mother's belly when the mother leaps from one branch to another branch, because of not having practiced it in this birth. And it is not possible to say that its birth immediately preceding was indeed that of a monkey, because of the scripture: 'Knowledge, action, and past wisdom follow him.' Therefore, like impressions, there is no destruction of all remaining karma, and thus residual karma is possible. Since it is so, therefore, by the remainder of the experienced karma... the letter 'ta' is to be seen as elided in 'ram'; the state of becoming rice, barley, etc., is difficult to escape; even more than that difficult escape, the connection with the body of the procreator is still more difficult to escape, this is the meaning; because when consumed by celibates, children, those devoid of virility, or old men, they are destroyed in the interval, due to the multiplicity of food-eaters. When sometimes, by a rare coincidence, they are eaten by procreators, then those who have attained the state of the procreator find the manifestation of their karma. How? Whoever indeed eats the food associated with the souls carrying residual karma becomes the procreator; and he who discharges semen into a woman during the fertile season, the soul becomes that very form, taking on that very shape; the predominance of the shape of his limbs is called 'bhūyaḥ' (becoming more); having entered inside the womb of the woman in the form of semen, the soul with residual karma takes on the shape of the procreator because the semen is conditioned by the shape of the procreator, according to another scripture: 'The vital energy is gathered from all the limbs.' Hence, it takes on the shape of the procreator, this is the meaning. For indeed, from a man a man is born, and from a cow an offspring of bovine shape is born, not of another species; therefore it is logical that it becomes that very form.
Chāndogyopaniṣadbhāṣyam· Leaf 7.116· bhāṣya
ये त्वन्ये अनुशयिभ्यश्चन्द्रमण्डलमनारुह्य इहैव पापकर्म- भिर्घोरैर्व्रीहियवादिभावं प्रतिपद्यन्ते, पुनर्मनुष्यादिभावम्, तेषां नानुशयिनामिव दुर्निष्प्रपतरम् । कस्मात् ? कर्मणा हि तैर्व्रीहियवादिदेह उपात्त इति तदुपभोगनिमित्तक्षये व्रीह्यादि- स्तम्बदेहविनाशे यथाकर्माज्जितं देहान्तरं नवं नवं जलूकाव-
In plain words
There is another class of souls who never ascend to the moon. Because of their dark and terrible deeds, they are reborn directly here on earth as plants like rice and barley, and only later return to human form. For these souls, escaping the plant state is not nearly as difficult as it is for the virtuous souls who are merely descending through the rain. Why? Because for these sinful souls, the plant body is an actual punishment-birth earned by their own karma. Once the karmic debt of that specific suffering is paid and the stalk of rice is cut down, they immediately move on to a fresh body earned by their remaining deeds—gliding smoothly from one form to the next, just like a leech stepping from one leaf to another.
Close to the Sanskrit
But those others, different from the souls with residual karma, who do not ascend to the orb of the moon, and who, right here on earth, due to their terrible evil deeds, attain the state of being rice, barley, etc., and subsequently the state of being human, etc.—for them, it is not so exceedingly difficult to escape as it is for the souls with residual karma. Why? Because indeed, by their own karma, the body of rice, barley, etc., was acquired by them as an actual birth; therefore, when the karmic cause for that experience is exhausted, and upon the destruction of the body of the clump of rice, etc., they enter a new, fresh body earned in accordance with their past deeds, just like a leech.