Then Sunetta developed love for seven years. Having done so he did not return to this world for seven eons of cosmic expansion and contraction. As the cosmos contracted he went to the realm of sublime luminosity. As it expanded he was reborn in an empty mansion of divinity. There he was the Divinity, the Great Divinity, the vanquisher, the unvanquished, the universal seer, the wielder of power. He was Sakka, lord of gods, thirty-six times. Many hundreds of times he was a king, a wheel-turning monarch, a just and principled king. His dominion extended to all four sides, he achieved stability in the country, and he possessed the seven treasures. He had over a thousand sons who were valiant and heroic, crushing the armies of his enemies. After conquering this land girt by sea, he reigned by principle, without rod or sword. Yet even though Sunetta lived so long, he was not free from rebirth, old age, and death, from sorrow, lamentation, pain, sadness, and distress. He was not free from suffering, I say.

Why is that? Because of not understanding and not penetrating four things. What four? Noble ethics, immersion, wisdom, and freedom. These noble ethics, immersion, wisdom, and freedom have been understood and penetrated. Craving for continued existence has been cut off; the leash to existence is ended; now there’ll be no more future lives.”

That is what the Buddha said. Then the Holy One, the Teacher, went on to say:

“Ethics, immersion, and wisdom,

and the supreme freedom:

these things have been understood

by Gotama the renowned.

And so the Buddha, having insight,

explained this teaching to the mendicants.

The Teacher has made an end of suffering;

seeing clearly, he is quenched.”

Numbered Discourses 7.67 7. The Great Chapter The Simile of the Citadel

“Mendicants, when a king’s frontier citadel is well provided with seven essentials and gets four kinds of sustenance when needed, without trouble or difficulty, it is then called a king’s frontier citadel that cannot be overrun by external foes and enemies.

With what seven essentials is a citadel well provided?