What is the origin of '日' as a curse word?

Question

I read a bunch of answers on 百度知道 but they are all very vague, indecisive and unauthoritative.

1

为什么人们喜欢用那字，那是因为用的人多，人们大多都没有自己的想法，别人说什么，别人什么说地多，他觉得不用就是落伍了。就这样，时间一长就很多人在说了，而且觉得自己特牛，会用那字。恨不能见谁都说。这不是很幼稚吗。 就像“晕”字，现在人们聊天也老喜欢用，跟那是差不多的。只是骂人跟觉得别人不懂表达的区别。 一楼那人说这跟日本有关系。这应该有关系。 但是这肯定是没有什么可查的。谁都不知道是怎么用起来的。 如果真的是抵触日本情绪，那用这字来骂同胞，真让人搞不懂！

2

西北一带都用这个字骂人的，意思都是一样的，其实这个”日”字并不是正确的，真只表达这个意思的那个”日”是一个”尸”字头的字，至于到底怎么写就不记得了，曾经在红楼梦里见过的，康熙字典里应该能查的到的．．．．汉语里很多关于”性”方面的字都是”尸”字头的，只是现代汉语里已经不常见了 有一种解释为骂日/本/人

3

日是象形字，可分成“口”和“一”，口是女性性器官的象形意思，“一”就不用讲了，一插进口，你也懂了，就是操。

My guess was that it had to do with Chinese peoples hatred of Japanese people and thus becoming a curse word. So whats the deal? Where does this word come from?

Answer 1

日 sounds like 入 when stressing the vowels. Compare with the character 肏 for the literal meaning of 入 in this context.

Answer 2

No, 日 doesn't related to any curse word, it just mean "sun" in Chinese. And I never heard someone use it as a curse word in Hong Kong.

Answer 3

Actually the Chinese chanters is actually from 象形文字 slowly become traditional Chinese character then simplified Chinese characters. for more accurate information you may do more research on 象形文字 so that you will understand the transformation process of the character characters .I think it will help.

Edit : I did some of research.. I dont think the word 日 got to do anything with Japanese This is what I found “日”字就像一个圆形，中间有一点，很像人们在直视太阳时，所看到的形态。