AN 3.76. Existence
Venerable Ananda approached the Buddha, bowed to him, and sat down to a side. He then asked: “Venerable sir, you mentioned existence, but how is there existence?”
“Ananda, would existence in the sensual worlds occur if there were no deeds that ripened in the sensual realm?”
“No, sir.”
“So with deeds as the field, consciousness as the seed, and craving as the moisture, the consciousness of beings who are obstructed by ignorance and chained by craving gets planted in the lower realm. That is how existence in a future life is produced.
Would existence with form occur if there were no deeds that ripened in the form realm?”
“No, sir.”
“So with deeds as the field, consciousness as the seed, and craving as the moisture, the consciousness of beings who are obstructed by ignorance and chained by craving gets planted in the middle realm. That is how existence in a future life is produced.
Would existence without form occur if there were no deeds that ripened in the formless realm?”
“No, sir.”
“So with deeds as the field, consciousness as the seed, and craving as the moisture, the consciousness of beings who are obstructed by ignorance and chained by craving gets planted in the higher realm. That is how existence in a future life is produced.
Ananda, that is how existence comes to be.”