Job 30:20-21
I cry unto thee, and thou dost not hear me: I stand up, and thou regardest me [not]. Thou art become cruel to me: with thy strong hand thou opposest thyself against me.

Proverbs 11:17
The merciful man doeth good to his own soul: but [he that is] cruel troubleth his own flesh.

Proverbs 12:10
A righteous [man] regardeth the life of his beast: but the tender mercies of the wicked [are] cruel