Among 9 jhanas which is deep sleep?
I've got a simple answer for you: Sleep is not a jhāna. The Buddha never says, not in Pāli not in Chinese not in Sanskrit, that sleep is a jhāna. Sleep is also not nibbāna. Sleep is also not nirodha. You just forget your dreams when you wake up and it seems like you were up to &quot;nothing,&quot; but your mind was quite active despite you not remembering it.