Saṁyutta Nikāya 15.17 2. Dutiyavagga Bhaginisutta

Sāvatthiyaṁ viharati …pe…

At Sāvatthī.

“na so, bhikkhave, satto sulabharūpo yo nabhaginibhūtapubbo …pe…

“It’s not easy to find a sentient being who in all this long time has not previously been your sister. …

alaṁ vimuccitun”ti.

This is quite enough for you to become disillusioned, dispassionate, and freed regarding all conditions.”

Sattamaṁ.