Majjhima Nikaya 4:37
SUJATO‘ahaṁ nu khosmi? No nu khosmi? Kiṁ nu khosmi? Kathaṁ nu khosmi? Ayaṁ nu kho satto kuto āgato? So kuhiṁ gāmī bhavissatī’ti?
‘Am I? Am I not? What am I? How am I? This sentient being—where did it come from? And where will it go?’