"Like they always say...the quality of mercy is not strained, it droppeth like a gentle dew from Heaven...well, you're not talking to a jerk you know!" - Barney
That is one of favorite Barney quotes. It is from the Merchant of Venice.
"The quality of mercy is not strained, it droppeth as the gentle rain from heaven upon the place beneath: it is twice blessed; it blesseth him that gives and him that takes: 'tis mightiest in the mightiest; it becomes the throned monarch better than his crown; his scepter shows the force of temporal power, the attribute to awe and majesty, wherein doth sit the dread and fear of kings, but mercy is above this sceptered sway, it is enthroned in the hearts of kings, it is an attribute of God himself, and earthly power dost then show likest God's when mercy seasons justice."
I once saw a movie about Nero, he was killing Christians right and left. He was told that mercy became a ruler and that the power of pardon was the greatest power of all. Supposedly Nero found this to his liking and started pardoning prisoners.