Word is that in some of the southern United States the addendum “Bless his heart” is a phrase that follows a subtle insult. For example, you might see, “My nephew Blair has had eight different jobs in two years, bless his heart.”
According to this blog
…the phrase, “bless his heart” or “bless her heart”, is a powerful weapon, allowing one to say some really nasty things about people as long as it’s tacked on the end…
And from this blog:
Another insult, although velveted and used by the sweetest-sounding ladies, is “bless his heart,” meaning, “I agree with the unkind thing you have just said but do not wish to say so myself.”
Example: “That newspaper columnist is as dumb as a box of rocks,” he said. “Bless his heart,” she replied.
Although that last one doesn’t exactly count as subtle. I guess in some cases the “Bless his heart” is more of a softener, a way of saying, “I’m not as mean as you think, because after I insulted him I wished him well.”
Here’s a story from last year about presidential candidate Mitt Romney’s learning about “Bless his heart:”
Romney’s best line is about his education in Southern manners and the fact that the region’s people are “most gentle with their choice of words.”
“People in the South have a way of saying things. Like ‘I can’t stand you and I hope you rot in hell.’ That’s said by saying, ‘Bless your heart,’” Romney observed.
That’s the slightly different way of using “Bless his heart” that I wanted to talk about. Something like, “Why, you told everyone at work what my childhood nickname was and how I got it? Bless your heart.”
Arabic has a very similar phrase: “God guide you.” It sounds all innocent, like all you’re doing is wishing a special little blessing. In reality, it means, God guide you, because you are so wrong.”
Here’s the Arabic: الله يهديك is “God guide you.” Pronounced, more or less, Ul-la yah-deek.
الله يهديه is “God guide him.” Ul-la yah-deeh.
الله يهديها is “God guide her.” Ul-la yah-dee-ha.
الله يهديهم “God guide them.” Ul-la yah-dee-hoom.
“They want to start a land war in Asia? الله يهديهم ”