The revival of the Hebrew language in Israel is the only example of a language's acquiring new first language speakers after it became extinct in everyday use for an extended period, being used only as a liturgical language. Even in the case of Hebrew, there is a theory that argues that "the Hebrew revivalists who wished to speak pure Hebrew failed. The result is a fascinating and multifaceted Israeli language, which is not only multi-layered but also multi-sourced. The revival of a clinically dead language is unlikely without cross-fertilization from the revivalists' mother tongue(s)."