1Thus have I heard. On one occasion the Blessed One was dwelling at Sāvatthī in Jeta's Grove, Anāthapiṇḍika's Park … .

"Bhikkhus, there are these four kinds of nutriment for the maintenance of beings that have already come to be and for the assistance of those about to come to be. [n.17] Bhūtanaṁ va sattanaṁ ṭhitiyā sambhavesinaṁ va anuggahaya. On sambhavesin as a future active participle formed from -esi(n), see Geiger, Pali Grammar, §193A, EV I, n. to 527, and CPD, s.v. -esi(n), (2). The commentators apparently were not acquainted with this grammatical form (of which only very few instances exist in Pali) and hence explain sambhavesin as if it was a bahubbihi compound made up of the noun sambhava and the adjectival termination -esin. Thus Spk comments on the above line: "Beings who have already come to be are those who have been born, been produced. Those about to come to be (or, on Spk's interpretation, ‘seekers of new existence’) are those seeking, searching for, a new existence, birth, production (sambhavesino ti ye sambhavaṁ jatiṁ nibbattiṁ esanti gavesanti)." What four?

The nutriment edible food, gross or subtle;
second, contact;
third, mental volition;
fourth, consciousness.
These are the four kinds of nutriment for the maintenance of beings that have already come to be and for the assistance of those about to come to be. [n.18] Spk: The nutriments are conditions (paccaya), for conditions are called nutriments (āhāra) because they nourish (or bring forth, āhāranti) their own effects. Although there are other conditions for beings, these four alone are called nutriments because they serve as special conditions for the personal life-continuity ajjhattikasantatiya visesapaccayatta. For edible food kabalinkara āhāra is a special condition for the physical body of those beings who subsist on edible food. In the mental body, contact is the special condition for feeling, mental volition for consciousness, and consciousness for name-and-form. As to what they bring forth (or nourish): Edible food, as soon as it is placed in the mouth, brings forth the groups of form with nutritive essence as the eighth (ojaṭṭhamakarūpani; an Abhidhamma term for the simplest cluster of material phenomena); the nutriment contact brings forth the three kinds of feeling; the nutriment mental volition brings forth the three kinds of existence; and the nutriment consciousness brings forth name-and-form on the occasion of rebirth.
In SN, nutriment is further discussed at SN12.12, 31, 63, and 64. For general remarks on the four nutriments, see too Vism 341,7–18 (Ppn 11:1–3). Nyanaponika Thera, The Four Nutriments of Life, offers a collection of relevant suttas with commentaries. Āhāra is also used in a broader sense of "special condition," without reference to the four nutriments, at SN46.51 and SN55.31.

2"Bhikkhus, these four kinds of nutriment have what as their source, sn.ii.12 what as their origin, from what are they born and produced?
These four kinds of nutriment have craving as their source, craving as their origin; they are born and produced from craving. [n.19] These four kinds of nutriment have craving as their source. Spk: Beginning with the moment of rebirth, these kinds of nutriment comprised in the individual existence (attabhava, the sentient organism) should be understood to originate by way of prior craving (purimataṇha; the craving of the previous life that generated rebirth). How? At the moment of rebirth, firstly, there exists nutritive essence oja produced within the arisen (bodily) form; this is the kammically acquired edible food originating from prior craving. Then the contact and volition associated with the rebirth-consciousness, and that consciousness itself, are respectively the kammically acquired nutriments of contact, mental volition, and consciousness originating from (prior) craving. Thus at rebirth the nutriments have their source in prior craving. And as at rebirth, so those produced subsequently at the moment of the first bhavaṅgacitta should be similarly understood.
On the conditioning role of the nutriments, see CMA 8:23. The commentarial explanation of how craving is the cause of the four nutriments seems roundabout. A simpler explanation, more consonant with the spirit of the suttas, might be that it is craving which impels beings into the perpetual struggle to obtain physical and mental nutriment, both in the present life and in future lives.

"And this craving has what as its source, what as its origin, from what is it born and produced?
This craving has feeling as its source, feeling as its origin; it is born and produced from feeling.

"And this feeling has what as its source … ?
Feeling has contact as its source and origin; it is born and produced from contact.

And this contact has what as its source … ?
Contact has the six sense bases as its source and origin; it is born and produced from the six sense bases.

And these six sense bases have what as their source … ?
The six sense bases have name-and-form as their source and origin; they are born and produced from name-and-form.

And this name-and-form has what as its source … ?
Name-and-form has consciousness as its source and origin; it is born and produced from consciousness.

And this consciousness has what as its source … ?
Consciousness has volitional formations as its source and origin; it is born and produced from volitional formations.

And these volitional formations have what as their source, what as their origin, from what are they born and produced?
Volitional formations have ignorance as their source, ignorance as their origin; they are born and produced from ignorance.

3"Thus, bhikkhus, with ignorance as condition, volitional formations come to be;
with volitional formations as condition, consciousness;
with consciousness as condition, name-and-form;
with name-and-form as condition, the six sense bases;
with the six sense bases as condition, contact;
with contact as condition, feeling;
with feeling as condition, craving;
with craving as condition, clinging;
with clinging as condition, existence;
with existence as condition, birth;
with birth as condition, aging-and-death, sorrow, lamentation, pain, displeasure, and despair come to be.

Such is the origin of this whole mass of suffering.

But with the remainderless fading away and cessation of ignorance comes cessation of volitional formations;
with the cessation of volitional formations, cessation of consciousness;
with the cessation of consciousness, cessation of name-and-form;
with the cessation of name-and-form, cessation of the six sense bases;
with the cessation of the six sense bases, cessation of contact;
with the cessation of contact, cessation of feeling;
with the cessation of feeling, cessation of craving;
with the cessation of craving, cessation of clinging;
with the cessation of clinging, cessation of existence;
with the cessation of existence, cessation of birth;
with the cessation of birth, aging-and-death, sorrow, lamentation, pain, displeasure, and despair cease.

Such is the cessation of this whole mass of suffering.

1Evaṁ me sutaṁ—​ ekaṁ samayaṁ bhagavā sāvatthiyaṁ vihārati jetavane anāthapiṇḍikassa ārāme …

"Cattārome, bhikkhave, āhārā bhūtānaṁ vā sattānaṁ ṭhitiyā sambhavesīnaṁ vā anuggahāya. Katame cattāro?

Kabaḷīkāro āhāro – oḷāriko vā sukhumo vā, phasso dutiyo, manosañcetanā tatiyā, viññāṇaṁ catutthaṁ. Ime kho, bhikkhave, cattāro āhārā bhūtānaṁ vā sattānaṁ ṭhitiyā sambhavesīnaṁ vā anuggahāya.

2Ime, bhikkhave, cattāro āhārā kiṁnidānā kiṁsamudayā kiṁjātikā kiṁpabhavā? Ime cattāro āhārā taṇhānidānā taṇhāsamudayā taṇhājātikā taṇhāpabhavā.

Taṇhā cāyaṁ, bhikkhave, kiṁnidānā kiṁsamudayā kiṁjātikā kiṁpabhavā? Taṇhā vedanānidānā vedanāsamudayā vedanājātikā vedanāpabhavā.

Vedanā cāyaṁ, bhikkhave, kiṁnidānā kiṁsamudayā kiṁjātikā kiṁpabhavā? Vedanā phassanidānā phassasamudayā phassajātikā phassapabhavā.

Phasso cāyaṁ, bhikkhave, kiṁnidāno kiṁsamudayo kiṁjātiko kiṁpabhavo? Phasso saḷāyatananidāno saḷāyatanasamudayo saḷāyatanajātiko saḷāyatanapabhavo.

Saḷāyatanañcidaṁ, bhikkhave, kiṁnidānaṁ kiṁsamudayaṁ kiṁjātikaṁ kiṁpabhavaṁ? Saḷāyatanaṁ nāmarūpanidānaṁ nāmarūpasamudayaṁ nāmarūpajātikaṁ nāmarūpapabhavaṁ.

Nāmarūpañcidaṁ, bhikkhave, kiṁnidānaṁ kiṁsamudayaṁ kiṁjātikaṁ kiṁpabhavaṁ? Nāmarūpaṁ viññāṇanidānaṁ viññāṇasamudayaṁ viññāṇajātikaṁ viññāṇapabhavaṁ.

Viññāṇañcidaṁ, bhikkhave, kiṁnidānaṁ kiṁsamudayaṁ kiṁjātikaṁ kiṁpabhavaṁ? Viññāṇaṁ saṅkhāranidānaṁ saṅkhārasamudayaṁ saṅkhārajātikaṁ saṅkhārapabhavaṁ.

Saṅkhārā cime, bhikkhave, kiṁnidānā kiṁsamudayā kiṁjātikā kiṁpabhavā? Saṅkhārā avijjānidānā avijjāsamudayā avijjājātikā avijjāpabhavā.

3Iti kho, bhikkhave, avijjāpaccayā saṅkhārā;
saṅkhārapaccayā viññāṇaṁ … pe …

Evametassa kevalassa dukkhakkhandhassa samudayo hoti.

Avijjāya tveva asesavirāganirodhā saṅkhāranirodho;
saṅkhāranirodhā viññāṇanirodho … pe …

Evametassa kevalassa dukkhakkhandhassa nirodho hotī"ti.

Paṭhamaṁ.