In this instance, “heart ” refers to the emotions, desires, and feelings of the inner person.
(‏ ام ١٧ :‏ ٣ ؛‏ ٢١ :‏ ٢‏ )‏ وَمَا يَجِدُهُ لَهُ أَبْلَغُ ٱلْأَثَرِ فِي عَلَاقَتِنَا بِهِ وَفِي مُسْتَقْبَلِنَا .‏