 Whether you speak in secrecy or allowed, it is all the same to Allah. He even knows the secrets that lie hidden in the hearts of people. Quran 67-13. These verses of the Quran clearly show that the even human heart can think and can understand. Yeah, of course, this is what it boils down to if you're a hardcore literalist, if you take everything literal, then you reduce it to the human organ, the heart. I would speak about intent here, I would speak about the spiritual intention that the human holds within what is in their hearts. Of course, this is a metaphor. This is clearly understood. We do not have to talk about a flesh organ. And surely Allah will know what is in your heart. I really don't understand why modern day Muslims want to make everything extremely literal and then it has to please science as well. Why?