This article discusses the application of shari’ah in the public sphere. Mainly, it evaluates arguments and practices of Islamic law regarding tolerance and harmony among interreligious communities. It has been claimed as important due to it seems no scholarly works which significantly reconstruct inspirational ideas and practices of Islamic law in terms of emphasising tolerance and harmony between Muslims and believers of other religions. Applying phenomenological approach, it examines ideas and behaviour of interfaith leaders in Malang, East Java, Indonesia. The leaders have been members of the Forum for Religious Harmony (FKUB). It arguably asserts that the interfaith leaders have played significant roles in maintaining religious harmony in the region. They have participatorily anticipated and resolved religious-based conflicts. For them, the participation is essential in order to maintain interreligious harmony born out of dialogue, acquaintance and mutual cooperation. In the practical level of mu'āmalah, they have tended to be tolerant and pluralist. Thus, their roles might be considered as a best practice for various peacebuilding efforts in Indonesia and other countries.