Bhai Banvali, and his brother Paras Ram, Brahmans by birth, were devotees of Guru Hargobind. They were professional physicians and, as says Bhai Mani Singh in his book "Sikhan di Bhagat Mala", they treated Sikhs and holy men free of charge, and went travelling preaching the word of the Guru.
Once they asked the Guru why attendance at holy congregation (sadh sangat) was given primacy when only shabad (the Holy Word) was efficacious enough to save all. Guru Hargobind answered: "It is in sangat alone that seekers meet gurmukhs, i.e. the enlightened ones, and receive from them prescriptions for a holy life."
1. Mani Singh, Bhai, Sikhan di Bhagat Mala. Amritsar, 1955
2. Santokh Singh, Bhai, Sn Gur Pratap Suraj Granth. Amritsar, 1926-37