Who Was Rabbeinu Yakir, and Why Did His Students Change His Name?

Anyone studying halachic literature will often find rulings attributed to "Rabbeinu Yakir." The author of the "Mordechai" frequently cites his rulings. The "Mordechai" is considered a work that centralizes the customs of Ashkenaz, which is why the Rama often references him. But who is Rabbeinu Yakir?

Rabbeinu Yakir was one of the great Tosafists, but anyone studying the Tosafot will not find his name mentioned even once. Why?

The reason is both original and interesting: His name was Rabbi Ephraim ben Rabbi Yitzchak ben Rabbi Avraham of Regensburg, and he is often mentioned in the Tosafot under the name "Rabbeinu Ephraim." However, when the "Mordechai" was written, several scholars were known as "Rabbeinu Ephraim." One of them was Rabbi Ephraim, a student of the Rif, who was a contemporary of Rabbi Ephraim ben Rabbi Yitzchak. To avoid confusion, his students, who loved their teacher dearly, decided to call him "Rabbeinu Yakir," based on the verse 'Yakir Li Ephraim' ("Ephraim is a precious son to me").

Even in the Tosafot, Rabbeinu Ephraim has a special nickname: sometimes he is referred to as "Rabbeinu Ephraim the Mighty." This nickname was given to him because he was strong in matters of halacha; his innovations were surprising and far-reaching, and he would stand his ground and argue even with the greats of the generation and with ancient community customs, as we'll mention further on.

Rabbeinu Ephraim was born in France and studied in the city of Lothere (now "Lorraine"), in the yeshiva of Rabbeinu Tam, the grandson of Rashi and a leading Tosafist. He was a fellow student of Rabbeinu Tam, who sometimes asked him questions. Rabbeinu Ephraim was not content with just one teacher and sought to learn another style of study, leading him to move to Germany, to the city of Speyer, where he learned at the yeshiva of Riva, a student of the holy Rashi, the first of the Tosafists. Later, he joined the beit din of Riva's grandson.

The first major controversy that arose from his innovation was in the city of Speyer, a central city in Jewish life for many years. Jews had lived there for many generations, and their custom was to avoid buying bread from local bakeries because the bakers used wine dregs to leaven the dough, and the wine was considered forbidden. But when Rabbeinu Ephraim studied the Tractate Avodah Zarah, he concluded from the topic of "Yud Bet Chodesh" that dregs that had dried for twelve months lost their status as food, and thus the prohibition was nullified, making the local bread permissible. The elderly Rabbeinu Tam heard of this innovation and was upset with him, as reported in the Tosafot (Avodah Zarah 34), and even compared the ruling to 'a rebellious and stubborn son.' But Rabbeinu Ephraim did not back down in the face of his great teacher and stood firm in his position. The rabbis of Speyer, Rabbi Shmaria of Speyer and Rabbi Avraham ben Shmuel the Pious (father of the famous Rabbi Judah the Pious, from the Kalonymos family), openly opposed Rabbeinu Ephraim. How dare he permit a prohibition that past sages had forbidden and had been observed for generations?

Rabbeinu Ephraim did not give up, but he had to leave the city to avoid maintaining a conflict. He moved south to the city of Worms, gathered communities of students there, but there he got entangled in an opposite controversy: the communities of Ashkenaz along the Rhine River had always eaten the fat of the stomach. The Torah forbids, as is known, eating the fat of the kidneys, but the fat on the stomach was not prohibited. However, Rabbeinu Ephraim decreed that even the stomach fat was forbidden by rabbinic law. Opposing him was his student, Rabbeinu Yoel, who defended the Rhine communities' custom. The debate was lengthy and heated, and finally, it was resolved that each side would maintain its custom. The Rhine communities would continue to eat, and anyone not from those communities would not eat the stomach fat. The most surprising resolution: those who are stringent should not refrain from using the utensils of those who are lenient; they did not adopt the ban on the utensils.

He also introduced a new practice in the Worms community: since ancient times, they blessed over myrtle on the Havdalah after Shabbat, but Rabbeinu Ephraim blessed on other spices, and as is common today, any spices are suitable for Havdalah.

One ruling of Rabbeinu Ephraim, which he later retracted, became very famous in the halachic literature. It concerned the eating of burbot fish. Part of the livelihood and diet of the Rhine region's inhabitants came from fish. The burbot is from the catfish family, and it appears not to have fins. However, it is known that in its initial stage of development, it does have fins, which later fall off. The burbot was very affordable, allowing the poor to make use of it, but what is the law for fins that fall off? Rabbeinu Ephraim pondered this and ruled that it is permissible to eat it, but the next day, he gathered the local sages and announced that he was retracting his decision, and the fish was prohibited. Why? Because in a dream, it was shown to him, "May blessing come to you for feeding Israel with creeping creatures," the word "blessing" was meant ironically, and the dream warned him not to lead the masses into sin. Poskim use this case as an example in the question of whether it is permissible to rely on dreams for halacha.

Rabbeinu Ephraim agreed with one particular innovation: when the Jews of Germany had the means, they would beautify and adorn synagogues. Rabbeinu Yoel noticed that the latest trend in synagogue artwork included figures of impure horses and birds, as was the case in the synagogue of Cologne (Köln). Is this permissible? Is there not an issue with assimilating gentile and impure images? Rabbeinu Ephraim replied that it is permissible without concern.

Another famous ruling of his is that we do not say "a forbidden piece becomes forbidden completely." Thus, the Shulchan Aruch rules. The Rama, however, holds like Rabbeinu Tam, maintaining that in prohibitions "a forbidden piece becomes forbidden completely," a very significant ruling in the laws of mixtures, where there is a difference between the Ashkenazi custom following Rabbeinu Tam and the Sephardi custom adopting the view of Rabbeinu Ephraim. He also ruled that a non-Jew is considered trustworthy to testify if it is known that they do not lie.

Indeed, Rabbeinu Ephraim was a mighty warrior in the battle of Torah, and in poetry, he was one of the marvels of his generation. One of his famous poems is "Avotai Ki Vachlu Bashehem Elokai Tzuri," recited on the Tenth of Tevet, as well as "Im Efes Reba HaKen," recited in the Selichot. The poems are ingenious in their unique use of language and polished rhymes. Authentic Ashkenazim say during Chanukah also the poem "Shnei Zaitim," one of the highlights of his creative work.