Sanhedrin 111 - Does One Have to Fulfill the Entire Torah?
The Ten Tribes are not destined to ever return from their place of exile, because God " cast them to another land, as this very day ." Just as the day goes, never to return, so the Ten Tribes go, never to return - these are the words of Rabbi Akiva. Rabbi Eliezer, however, says that the phrase "as this very day" implies that just as the day darkens and then becomes light, so too the Ten Tribes, for whom it is dark, will likewise one day have light. Said Rabbi Yochanan, "Rabbi Akiva has abandoned his usual generosity of spirit."
Isaiah said, " Therefore Sheol (another name for Gehinnom) has expanded her desire and opened wide her mouth without measure. " Resh Lakish explained "without measure" as saying that whoever leaves even a single law unfulfilled is condemned to punishment in Gehinnom. Rabbi Yochanan said to him, "God, the Master, is not pleased with you saying such things about his subjects." Rather, if one learned no more than a single law, he will be spared the punishment of Sheol.
Art: Jozef Israels - Grief Out of Darkness into Light