In the previous Halachot, we have explained in a general manner the rule of “When in doubt regarding a blessing, do not bless,” i.e. that if one is uncertain whether or not one has recited a blessing on the food one is eating, one should not recite the blessing again, for this constitutes possibly entering the realm of mentioning Hashem’s name in vain by reciting the blessing a second time since it is possible that one has already recited the blessing. Nevertheless, one is permitted to continue eating the food in front of him based on this rule of “When in doubt regarding a blessing, do not bless.” Since the entire basis for the requirement of reciting blessings is only rabbinic and not by virtue of a Torah law, anytime one is in doubt, we rule that one should not recite the blessing again. We have written that all this applies to blessings which are a result of a rabbinic enactment; however, regarding Birkat Hamazon which is a Torah obligation (for as long as one has eaten and is satisfied as a result of the food one has eaten, one is obligated to recite Birkat Hamazon on a Torah level, as the Torah states, “And you shall eat and you shall be satisfied and you shall bless”), even if one is unsure if one has recited it or not, one must recite Birkat Hamazon again, for “When in doubt regarding a Torah law, one must act stringently.”
Is the Entire Birkat Hamazon a Torah Obligation?
Regarding what we have written that reciting Birkat Hamazon is a Torah obligation, in truth, this only applies to the first three blessings of Birkat Hamazon: “Hazan Et Hakol,” “Al Ha’aretz Ve’al Hamazon,” and “Boneh Yerushalayim.” However, the fourth blessing, known as “Hatov U’Metiv” (“La’ad Ha’el Avinu Malkeinu” etc.), is not based on a Torah obligation; rather, our Sages enacted that it be recited within Birkat Hamazon. Based on this, it would seem clear that one should not recite this blessing again when in doubt based on the rule of “When in doubt regarding a blessing, do not bless.”
The Magen Avraham’s Opinion
However, the Magen Avraham (Chapter 184) writes that whenever one is required to repeat Birkat Hamazon as a result of one’s uncertainty, one must repeat the Hatov U’Metiv blessing as well, for if we were to say that one should not repeat this blessing, people will come to treat it lightly as though it is of less importance than the rest of Birkat Hamazon. He quotes this in the name of such great earlier Acharonim as the Maharash Hayun and Mahari Ha’Levi. Many Poskim rule likewise that although regarding other blessings we rule that “When in doubt, do not bless,” nevertheless, when blessings which one is obligated to recite by Torah law and blessings which are rabbinic enactments are mixed together, we rule that one must recite all of the blessings over again so that people will not come to treat the blessings which are not required by Torah law lightly.
The Lechem Mishneh’s Opinion
The Eliyah Rabba writes that he has found in the Sefer Lechem Mishneh that one should not repeat the Hatov U’Metiv blessing since it is not a Torah obligation. Similarly, the Sefer Olat Tamid writes that the simple understanding of Maran Ha’Shulchan Aruch who writes that one must repeat Birkat Hamazon “because it is a Torah obligation” seems to imply that only the part of Birkat Hamazon which is derived from Torah law must one repeat when in doubt; however, the fourth blessing which is not a Torah obligation should not be repeated in a case of doubt. Many other Poskim rule likewise that when in doubt, one only repeats the blessings which one is obligated to recite by Torah law alone; however, one should not repeat the fourth blessing which is only of rabbinic origin when in doubt.
Upon dealing lengthily with the various opinions in the Poskim and providing sources for each side, Maran zt”l concludes that one should not repeat the fourth blessing of Birkat Hamazon when in doubt; only the first three blessings of Birkat Hamazon should be recited when one is in doubt.
Summary: If one eats bread and is satiated as a result of the food he has eaten and is now uncertain whether or not he has recited Birkat Hamazon, one must repeat Birkat Hamazon. Nevertheless, only the first three blessings of Birkat Hamazon should be repeated; however, the fourth blessing of Birkat Hamazon, La’ad Ha’el Avinu Malkeinu, is not repeated.
We shall, G-d-willing, discuss the laws of women in this scenario in the following Halacha.