In the Spring and Autumn Period (chūn qiū 春秋时期,770-476 BC), the famous strategist Sun Wu (sūn wǔ 孙武) known as Sun Zi (sūn zǐ 孙子) came to see the King of the State of Wu (wǔ guǒ 吴国) , bringing along his great work The Art of War (sūn zǐ bīng fǎ 孙子兵法).

He offered to help turn the State of Wu into a more powerful kingdom by training a strong army for it.The king was not quite convinced and asked, "Can you try your method out on a small army?"
"Yes", Sun Wu answered.
"Can you try them out on some women?"
"Why not?"
Then the king called in one hundred and eighty maids of honor and ordered Sun Wu to train them.Sun Wu organized the young ladies into two teams and appointed two of the king's favorite concubines team leaders. Everyone was given a weapon and stood in line.

Then, Sun Wu asked these women, "do you know how to march forward, backward, to the left and to the right?"
"Yes, we do." They replied.
In spite of this, Sun Wu explained to them in great detail now to march in the four directions. He also told them time and again that they must obey orders and explained why.
Now, Sun Wu beat the drum and ordered the army to march to the right. To his disappointment, the young ladies who had never received military training before did not act as he had ordered but giggled. Sun Wu did not blame them but said in all seriousness: "It's the general's fault if he hasn't made himself clear." He then repeated several times what he had said a moment before.

Now, he beat the drum and gave an order to march to the left. The ladies giggled instead of taking his order. This time, Sun Wu said seriously: "Now the order has been made clear, so that's the leaders' faults not to obey that!" He ordered to behead the two leaders.

The king who was watching the training all the time was shocked and immediately sent someone to plead for mercy for his two concubines. But Sun Wu rejected the pleading. On his insistence, the two-team leaders were executed. Sun Wu appointed two new team leaders and went on with the training. Everybody turned very serious and acted correctly to Sun's orders, just like soldiers.

From then on, the troops of the state of Wu were trained by Sun Wu and became stronger and stronger.

From how Sun Wu repeated his orders comes the idiom "Repeating an order time and again".

      春秋时期，著名的军事家孙武（即孙子）带着他的著作《孙子兵法》去见吴王。他提出要帮助吴国训练一支强大的军队，使吴国成为一个更加强大的国家。 吴王并不是非常相信他，问道：“你能用一支小型军队操演一下你的方法吗？”孙子回答说：“可以。”
“能用女子来操演吗？”
“可以啊。”

      于是吴王召来一百八十名宫女，命令孙武来训练她们。孙武将宫女分为两队，叫吴王的两个宠姬担任队长。给他们每人一件武器，排成一行。接着，孙武问她们，“你们知道如何向前，向后，朝左，朝右？”她们说：“知道呀。”但是，孙武还是把这些详详细细的向她们解释了一遍。他还重复了许多遍，告诉她们必须遵守命令，也解释了原因。

      然后，孙武敲鼓，命令队伍朝右。令他失望的是，那些从未接受过军事训练的年轻女子只是哈哈的笑，没有遵守他的命令。孙武并没有责备她们，只是严肃的说：“号令没有交代清楚，是将军的错误。”于是重新把刚作的解释又重复了许多遍。

      他又击鼓，命令队伍朝左。那些女子还是哈哈的笑，不听号令。这回，孙武严肃的说：“号令即明，不遵守就是头领的错。”他下令将两个队长斩首。一直在观看操演的吴王大惊，他急忙派人替这两个宠姬求情。但孙武拒绝了。在他的坚持下，这两个队长被处死。他又重新指定了两名队长，继续操演。这回，每个人都非常严肃，按照号令正确的进行操演，就像是士兵一样。自此，吴国的军队就由孙武训练，并且日益强大。

      而成语“三令五申”这个成语就是由孙武反复说明他的命令而来。

三令五申 (sān lìng wǔ shēn)
【翻译】Repeated injunctions.
【释义】令：命令；申：表达，说明。多次命令和告诫。
【例句】经理三令五申地让他一定要把货物安全送到，但他还是把货物给弄丢了。
【近义词】发号施令、千叮万嘱
【反义词】敷衍了事