The Gemara in Sotah (47a) says something shocking: 

  “As a reward for the forty-two korbanot that Balak offered, he merited that Rut
descended from him… from whom came Shlomo HaMelekh.” 

 Wait… what? 

 Balak—the man who tried to annihilate Am Yisrael—gets to be the great-grandfather of Mashiach? 

  If you told Balak that his offerings would lead to the birth of David HaMelekh, he would’ve canceled the korbanot and grilled the animals for himself. 

 He didn’t intend good. So why the reward?