What is the origin of the idiom "have one's interests at heart" and when to use it?

The idiom "have one's interests at heart" has evolved naturally over time as a way to express the concept of genuine care and concern for someone's well-being or desires. The phrase reflects the inherent human tendency to prioritize the interests and happiness of those we value or have a close relationship with. Its origin lies in the intrinsic qualities of empathy, compassion, and trust that have been integral to human interactions throughout history. Over time, the idiom has become ingrained in everyday language, representing the idea of selflessness and genuine intentions towards another person's best interests.