The army marshal Ziyu68 spoke to the Song ruler, saying, “When King Wen70 attacked Chong, he put the city’s walls under attack but after three day-cycles [thirty days] was still unable to take it.
He retreated, cultivated his virtue, and then attacked again. This time the city fell to him as soon as he reached its walls.
Are there not currently insufficiencies in your virtue?
Why don’t you retreat, cultivate your virtue, and then attack when there are no more imperfections?” Wu Zi Xu Urges Helü to Press His Attack on Chu