It’s a question the rabbis grappled with, and in Vayikra Rabbah 36, we find some fascinating—and differing—answers.
The text explores just how long the merit, the z’chus, of the patriarchs Abraham, Isaac, and Jacob endures. It's not a simple, straightforward answer, is it?
Rabbi Tanhuma, quoting Rabbi Ḥiyya bar Menaḥama (or some say Rabbi Berekhya bar Ḥelbo, citing Rava bar Zavda), suggests it lasted until the time of Yehoahaz, a king of Israel. The proof? A verse from II Kings 13:23: “But the Lord showed them favor and had mercy on them…until now.” That "until now," they say, marks the limit of the patriarchs' influence.
But Rabbi Yehoshua ben Levi disagrees! He argues that the patriarchs' merit lasted until the time of Elijah. He points to I Kings 18:36, where Elijah calls upon "Lord, God of Abraham, Isaac, and Israel." The very invocation, he suggests, shows their power was still potent then.
And the debate continues! Shmuel says the merit lasted until Hosea. He interprets Hosea 2:12 ("Now I will reveal her repulsiveness in the eyes of her paramours, and no man will deliver her from My hand") through a clever connection. The "man" referenced, he argues, echoes how Abraham (Genesis 20:7), Isaac (Genesis 24:65), and Jacob (Genesis 25:27) are each called "man" in different verses. Thus, the verse in Hosea speaks to the end of their protective power. It's that kind of interpretive move that makes studying these texts so rewarding.
Then, Rabbi Yudan offers another perspective, suggesting the merit lasted until Hezekiah. He cites Isaiah 9:6: “For abundant authority and for unending peace…from now, forever; the zealotry of the Lord of hosts will accomplish this.” Rabbi Yudan understands this to mean that after Hezekiah, God's own zealotry would take over, as the patriarchs' merit had run its course. The implication is quite stark: at some point, we need to rely on our own actions, not just the legacy of our ancestors.
But Rabbi Yudan doesn’t leave us there. In the name of Rabbi Berekhya, he adds a crucial piece of advice: "If you see that the merit of the patriarchs has failed and the merit of the matriarchs has faltered, go and cleave to acts of kindness." He finds support in Isaiah 54:10: "For the mountains will move, and the hills will collapse...My kindness will not be moved from you." The mountains are the patriarchs, the hills are the matriarchs, but God's kindness—manifested in our own acts of chesed, of loving-kindness—can endure.
Finally, Rabbi Aḥa offers the most optimistic view: the merit of the patriarchs endures forever! He points to Deuteronomy 4:31: “For the Lord your God is a merciful God, He will neither forsake you, nor destroy you, nor forget the covenant of your patriarchs.”
So, what are we to make of all these different opinions? Is there a definitive answer? Perhaps the point isn't to pinpoint an exact date, but to recognize that while we benefit from the legacy of those who came before us, our own actions matter, too. The merit of the ancestors might fade, but the potential for kindness, for chesed, remains ever-present. Perhaps that's the enduring legacy we should strive for.