Well... hati could also mean liver in sense of organ and heart in sense of feeling. There's etymology for why that happens in net.
Still, it's also used for jokes here too.
I was just pointing out the potential for jokes, of course, but I wonder whether the liver was seen as the seat of the emotions at some point in Indonesia (or India, or the Dar-ul-Islam). It was the seat of the appetites according to most ancient Greek authorities, I think.
It gets a lot of puns from the good one to bad one, hahaha. The popular one is "makan hati" (eat heart/liver) which means "sulk" in English, it will be responded (or you as the speaker would follow up with) "that's tasty" or something like that.
Yeah, it might be from the ancient Greek as well (Arab got it from there after all). While other languages move to "heart," we still stuck at "liver." Still if you notice, English's "live" and "life" are similar to "liver" too.