That last one is from Ecclesiastes 12:1,which points out the fact many of the inscriptions are not original.
May there be just enough clouds in your sky,
To make a beautiful sunset.
圣经中的传道书
不过词句不完全一样啊...但可能也是最原始的出处
也在其它一些网站上看到很多同样意思但是说法略有不同的,比如：
"May you have just enough clouds in your life to be left with a beautiful sunset."
作者：Unknown