Bageshwar Dham Sarkar

Why is seva called the heart of dharma, and how did Hanuman ji show it?

Seva is the heart of dharma

The essence of dharma is seva, and Hanuman ji did exactly this. He chose to stay on earth for Ram's katha and Ram's seva rather than go to Goloka.

The essence of dharma is seva; the meaning of dharma is seva. Hanuman ji did exactly this.