It rains when Heaven deems fit, mother remarries when she wants to--a popular saying often heard in China, what's the source of it?

It comes from a legend.

In ancient times there was a scholar called Zhu Yaozong who came first in the highest imperial examination. Conferred the title Number One Scholar, he was chosen to be the emperor's son-in-law. By convention, he would first return to his hometown in silken official robes. Before he left he begged the emperor for a favor--to erect a chastity archway in honor of his widowed mother. His request was granted.

His mother, however, appeared uneasy when she was told about the chastity archway. She had to admit that she was determined to remarry and her would-be husband was Zhu's former tutor to whom he owed a great deal. Devastated by the idea Zhu fell to his knees in front of his mother: “Mom. That's absolutely impossible. How could I face others if you do so. Besides, it will mean I have deceived the emperor--a felony deserving death penalty.”

As he was caught in a fix and nothing could be done, his mother sighed:“Since things have come to a head，let's trust to luck.” She then took off a skirt and handed it to him, saying:“Wash it tomorrow and dry it in the sun for a day. If it dries up by dawn the next morning, I'll drop the idea; if not, you are not to interfere, for it's the will of Heaven.”

That day was very fine with the sun shining brightly in a clear sky. But during the night clouds gathered and the sky became overcast. It broke into a violent shower towards daybreak. The skirt remained wet long after dawn. His mother said to him seriously:“Look here, son. It rains when Heaven deems fit, mother remarries when she wants to. The will of Heaven is not to be opposed.” So Zhu could do nothing but report to the emperor and express his readiness to be punished. The emperor was greatly surprised by the story and issued an imperial decree:“He who is unaware is not liable. Since the match has been made by Heaven, it has to be allowed.”

傳說古時候有個名叫朱耀宗的書生，進京趕考高中狀元。皇上殿試將他招為駙馬。按慣例，朱耀宗一身錦繡新貴還鄉。臨行前，朱耀宗請求皇上為多年守寡一直不嫁的母親豎立貞節牌坊。皇上準允所奏。

當朱耀宗向娘述說了豎立貞節牌坊一事后，朱母露出了不安的神色，于是說出了想要嫁給朱耀宗的恩師張文舉的想法。朱耀宗頓時跪在娘的面前：“娘，這千萬使不得。您改嫁叫兒的臉往哪擱? 再說，欺君之罪難免殺身之禍啊。”

正值左右為難、無可奈何之際，朱母不由長嘆一聲：“聽天由命吧。”她隨手脫下身上一件羅裙，告訴朱耀宗說：“明天你替我把裙子洗干凈，一天一夜曬干。如果裙子曬干，我答應不改嫁；如果裙子不干，天意如此，你也不用再阻攔了。”

這一天，晴空朗日，誰知當夜陰云密布，天明下起暴雨，裙子始終是濕漉漉的。朱耀宗心中叫苦不迭，知是天意。朱母則認認真真地對兒子說：“孩子，天要下雨，娘要嫁人，天意不可違!”朱耀宗只得將母親和恩師的婚事報告皇上，請皇上治罪。皇上連連稱奇，降道御旨：“不知者不怪罪，天作之合，由他去吧。”