Buddha teaches seven things make a nation become prosperous

King Ajātasattu
Thus I heard:
At one time the Gracious One was living near Rājagaha on the Vultures’ Peak Mountain.
Now at that time the Magadhan King Ajātasattu, the son of Lady Wisdom, had a desire to attack the Vajjians. He said this: “I will annihilate these Vajjians, who are so successful, so powerful, I will destroy the Vajjians, I will bring about the downfall and destruction of the Vajjians”.
Then the Magadhan King Ajātasattu, the son of Lady Wisdom, addressed the Magadhan chief minister the brahmin Vassakāra, saying:
“Go, brahmin, and approach the Gracious One, and after approaching worship the Gracious One’s feet in my name, and ask whether he is free from sickness, free from illness, in good health, and living comfortably, and say: ‘The Magadhan King Ajātasattu, the son of Lady Wisdom, reverend Sir, worships with his head at the Gracious One’s feet, and asks whether you are free from sickness, free from illness, in good health, and living comfortably.’
And say this: ‘The Magadhan King Ajātasattu, the son of Lady Wisdom, reverend Sir, desires to attack the Vajjians. He says this: “I will annihilate these Vajjians, who are so successful, so powerful, I will destroy the Vajjians, I will bring about the downfall and destruction of the Vajjians.” And just what the Gracious One says to you, after learning it well, you must inform me, for the Realised Ones do not speak falsely.”
“Very well, dear Sir,” and the Magadhan chief minister the brahmin Vassakāra, after replying to the Magadhan King Ajātasattu, the son of Lady Wisdom, and having many great and august vehicles prepared, and mounting those great and august vehicles, departed with those great and august vehicles from Rājagaha, and after approaching by vehicle to the Vultures’ Peak Mountain as far as the ground for vehicles would allow, and descending from the vehicles, he approached the Gracious One by foot, and after approaching, he exchanged greetings with the Gracious One, and after exchanging courteous talk and greetings, he sat down on one side. While sitting on one side, the Magadhan chief minister the brahmin Vassakāra said this to the Gracious One:
“The Magadhan King Ajātasattu, the son of Lady Wisdom, dear Gotama, worships with his head at dear Gotama’s feet, and asks whether you are free from sickness, free from illness, in good health, and living comfortably.
The Magadhan King Ajātasattu, the son of Lady Wisdom, dear Gotama, desires to attack the Vajjians. He says this: ‘I will annihilate these Vajjians, who are so successful, so powerful, I will destroy the Vajjians, I will bring about the downfall and destruction of the Vajjians’”.
2: Seven Things which Prevent Decline in the Vajjians
Now at that time venerable Ānanda was stood behind the Gracious One fanning the Gracious One. Then the Gracious One addressed venerable Ānanda, saying:

“Have you heard, Ānanda: ‘The Vajjians assemble regularly and assemble frequently?’” “I have heard this, reverend Sir: ‘The Vajjians assemble regularly and assemble frequently.’” “For as long, Ānanda, as the Vajjians will assemble regularly and assemble frequently surely growth, Ānanda, is to be expected for the Vajjians not decline.
Have you heard, Ānanda: ‘The Vajjians assemble unanimously, rise unanimously, and carry out their Vajjian duties unanimously?’” “I have heard this, reverend Sir, that the Vajjians assemble unanimously, rise unanimously, and carry out their Vajjian duties unanimously.” “For as long, Ānanda, as the Vajjians will assemble unanimously, rise unanimously, and carry out their Vajjian duties unanimously, surely growth, Ānanda, is to be expected for the Vajjians not decline.
Have you heard, Ānanda: ‘The Vajjians do not establish new laws that were not established, or cut off old laws that were established, and carry on with such laws as were accepted in the Ancient Vajjian Constitution?’” “I have heard this, reverend Sir: ‘The Vajjians do not establish new laws that were not established, or cut off old laws that were established, and they carry on with such laws as were accepted in the Ancient Vajjian Constitution.’” “For as long, Ānanda, as the Vajjians do not establish new laws that were not established, or cut off old laws that were established, and they carry on with such laws as were accepted in the Ancient Vajjian Constitution surely growth, Ānanda, is to be expected for the Vajjians not decline.
Have you heard, Ānanda: ‘The Vajjians honour the elders of the Vajjians, respect, revere, worship and think them worth listening to?’” “I have heard this, reverend Sir: ‘The Vajjians honour the elders of the Vajjians, respect, revere, worship and think them worth listening to.’” “For as long, Ānanda, as the Vajjians will honour the elders of the Vajjians, respect, revere, worship and think them worth listening to, surely growth, Ānanda, is to be expected for the Vajjians not decline.
Have you heard, Ānanda: ‘The Vajjians do not coerce and force their women and girls to dwell with them against their will?’” “I have heard this, reverend Sir: ‘The Vajjians do not coerce and force their women and girls to dwell with them against their will.’” “For as long, Ānanda, as the Vajjians will not coerce and force their women and girls to dwell with themagainst their will, surely growth, Ānanda, is to be expected for the Vajjians not decline.
Have you heard, Ānanda: ‘The Vajjians honour the Vajjian shrines amongst the Vajjians, both within and without the city, respect, revere, and worship them, and do not allow the righteous sacrifices that were formerly given, formerly made, to be neglected?’” “I have heard this, reverend Sir: ‘The Vajjians honour the Vajjian shrines amongst the Vajjians, both within and without the city, respect, revere, and worship them, and do not allow the righteous sacrifices that were formerly given, formerly made, to be neglected.” “For as long, Ānanda, as the Vajjians will honour the Vajjian shrines amongst the Vajjians, both within and without the city, respect, revere, and worship them, and do not allow the righteous sacrifices that were formerly given, formerly made, to be neglected surely growth, Ānanda, is to be expected for the Vajjians not decline.
Have you heard, Ānanda: ‘The Vajjians have made good arrangements in regard to the lawful protection, safety, and guarding of the Worthy Ones, so that Worthy Ones in the future can enter the realm, and having entered the Worthy Ones can live comfortably in the realm?” “I have heard this, reverend Sir: ‘The Vajjians have made good arrangements in regard to the lawful protection, safety, and guarding of the Worthy Ones, and that the Worthy Ones in the future can enter the realm, and having entered the Worthy Ones can live comfortably in the realm.” “For as long, Ānanda, as the Vajjians will make good arrangements in regard to the lawful protection, safety, and guarding of the Worthy Ones, and that the Worthy Ones in the future can enter the realm, and having entered, the Worthy Ones can live comfortably in the realm, surely growth, Ānanda, is to be expected for the Vajjians not decline.”
Then the Gracious One addressed the Magadhan chief minister the brahmin Vassakāra, saying: “At one time, brahmin, I was living near Vesālī near to the Sārandada Shrine and there I taught the Vajjians these seven things which prevent decline. For as long, brahmin, as the Vajjians maintain these seven things which prevent decline, and the Vajjians agree with these seven things which prevent decline, surely growth, brahmin, is to be expected for the Vajjians not decline.”
After this was said, the Magadhan chief minister the brahmin Vassakāra addressed the Gracious One, saying: “If the Vajjians, dear Gotama, were endowed with even one or the other of these seven things which prevent decline, surely growth is to be expected not decline, what to say about having seven things which prevent decline? The Vajjians cannot be overcome, dear Gotama, by the Magadhan King Ajātasattu, the son of Lady Wisdom, by war, but only through diplomacy, or through the breaking of an alliance. And now, dear Gotama, we shall go, as we have many duties, and there is much which ought to be done.”
“Now is the time, brahmin, for whatever you are thinking.” Then the Magadhan chief minister the brahmin Vassakāra, after greatly rejoicing and gladly receiving this word of the Gracious One, rose from his seat and departed.
Excerpts from The first chapter of The Discourse about The Great Emancipation. (Long Discourses - mahàparinibbànasutta)