Jews who long have drifted from the faith of their fathers... are stirred in their inmost parts when the old, familiar Passover sounds chance to fall upon their ears.

Heine is describing the tenacity of cultural and religious memory: even Jews who have assimilated or distanced themselves from Judaism can be unexpectedly moved by a sensory trigger—here, the familiar sounds of the Passover liturgy or song. The image suggests that identity is not only a matter of conscious belief but also of inherited language, ritual, and emotion that persists beneath intellectual doubt or social adaptation. In Heine’s hands, Passover functions as a symbol of collective origin and historical continuity; the “chance” hearing underscores how involuntary and deep this attachment can be, surfacing despite long estrangement.