"A learned man lost all his sources of income and was looking for a way to earn a living. The members of his community, who admired him for his learning and piety, suggested to him to serve as their cantor on the Days of Awe. But he considered himself unworthy of serving as the messenger of the community, as the one who should bring the prayers of his fellow-men to the Almighty. He went to his master the Rabbi of Husiatin and told him of his sad plight, of the invitation to serve as cantor on the Days of Awe, and of his being afraid to accept it and to pray for his congregation.

'Be afraid, and pray,' was the answer of the rabbi."

A.J Heschel, Man's Quest For God, Aurora Press, p.89. In a footnote to this passage Heschel refers to Man is Not Alone p 256, where this story also appears.