So I have heard. Evaṁ me sutaṁ—At one time, when he was first awakened, the Buddha was staying in Uruvelā at the root of the tree of awakening on the bank of the Nerañjarā River. ekaṁ samayaṁ bhagavā uruvelāyaṁ viharati najjā nerañjarāya tīre bodhirukkhamūle paṭhamābhisambuddho. There the Buddha sat cross-legged for seven days without moving, experiencing the bliss of freedom. Tena kho pana samayena bhagavā sattāhaṁ ekapallaṅkena nisinno hoti vimuttisukhapaṭisaṁvedī. When seven days had passed, the Buddha emerged from that state of immersion. In the first part of the night, he carefully applied the mind to dependent origination in forward order: Atha kho bhagavā tassa sattāhassa accayena tamhā samādhimhā vuṭṭhahitvā rattiyā paṭhamaṁ yāmaṁ paṭiccasamuppādaṁ anulomaṁ sādhukaṁ manasākāsi:

“When this exists, this comes to be; due to the arising of this, this arises. That is: “Iti imasmiṁ sati idaṁ hoti, imassuppādā idaṁ uppajjati, yadidaṁ—Ignorance is a requirement for choices. avijjāpaccayā saṅkhārā, Choices are a requirement for consciousness. saṅkhārapaccayā viññāṇaṁ, Consciousness is a requirement for name and form. viññāṇapaccayā nāmarūpaṁ, Name and form are requirements for the six sense fields. nāmarūpapaccayā saḷāyatanaṁ, The six sense fields are requirements for contact. saḷāyatanapaccayā phasso, Contact is a requirement for feeling. phassapaccayā vedanā, Feeling is a requirement for craving. vedanāpaccayā taṇhā, Craving is a requirement for grasping. taṇhāpaccayā upādānaṁ, Grasping is a requirement for continued existence. upādānapaccayā bhavo, Continued existence is a requirement for rebirth. bhavapaccayā jāti, Rebirth is a requirement for old age and death, sorrow, lamentation, pain, sadness, and distress to come to be. jātipaccayā jarāmaraṇaṁ sokaparidevadukkhadomanassupāyāsā sambhavanti. That is how this entire mass of suffering originates.” Evametassa kevalassa dukkhakkhandhassa samudayo hotī”ti.

Then, understanding this matter, on that occasion the Buddha expressed this heartfelt sentiment: Atha kho bhagavā etamatthaṁ viditvā tāyaṁ velāyaṁ imaṁ udānaṁ udānesi:

“When things become clear “Yadā have pātubhavanti dhammā, to the keen, meditating brahmin, Ātāpino jhāyato brāhmaṇassa; his doubts are dispelled, Athassa kaṅkhā vapayanti sabbā, since he understands each thing and its cause.” Yato pajānāti sahetudhamman”ti.

Paṭhamaṁ.