Mātusutta

Sāvatthiyaṁ viharati. “Anamataggoyaṁ, bhikkhave, saṁsāro …pe… na so, bhikkhave, satto sulabharūpo yo namātābhūtapubbo iminā dīghena addhunā. Taṁ kissa hetu? Anamataggoyaṁ, bhikkhave, saṁsāro …pe… alaṁ vimuccitun”ti. Catutthaṁ.

At Sāvatthī. “Mendicants, this transmigration has no known beginning. … It’s not easy to find a sentient being who in all this long time has not previously been your mother. Why is that? This transmigration has no known beginning. … This is quite enough for you to become disillusioned, dispassionate, and freed regarding all conditions.”