Question: If someone blesses me, such as by saying “Be well,” should I answer “Amen”?
Answer: The Mishnah Berura (Chapter 215, Subsection 9) quotes a Midrash which states that when one overhears another person praying for something or blessing someone else, one should answer “Amen.” It is for this reason that it is customary to answer “Amen” to the series of “Harachaman”s recited at the end of Birkat Hamazon.
This means that even if a given prayer or blessing is not an actual blessing established by our Sages and does not even contain the name of Hashem, it is nevertheless proper to answer “Amen” to that prayer or blessing. Indeed, it seems from the aforementioned Midrash that this is obligatory and not merely proper. Some Acharonim rule likewise.
On the other hand, the Netziv writes that this is not an actual obligation and is merely the proper thing to do, for by answering “Amen,” one strengthens the matter so that it truly comes to fruition (as Rashi on Shevuot 36a states). Maran Rabbeinu Ovadia Yosef zt”l rules likewise (in his Responsa Yechave Da’at, Volume 3, Chapter 9).
We should nonetheless point out that Maran zt”l was careful regarding this matter and when people would offer him various blessings, such as for a speedy recovery or that he never renders a mistaken ruling, he would answer “Amen.” He would even answer “Amen” to blessings offered by simple Jews. Similarly, whenever he blessed his grandchildren, he expected them to answer “Amen.” When they did not do so, he would, at times, point out to them that they should answer “Amen.”
The Gemara (Ketubot 65a) states that Rabbi Yochanan recounted that the daughter-in-law of Nakdimon ben Gurion, whose husband had passed away, once came to the Bet Din to request money for sustenance from her late husband’s estate. The Bet Din awarded her with “two Se’ah of wine for meat pudding,” i.e. a large sum of money since she was a respected and wealthy woman and such an amount befitted a woman of her stature.
She then turned to the sages sitting in the Bet Din and exclaimed, “May it be Hashem’s will that you award the same amount to your daughters!” However, the sages did not answer “Amen” to her blessing. The Gemara explains that the reason why they did not wish to answer “Amen” to her blessing was because her husband had passed away without bearing children leaving her to await Yibbum (levirate marriage) from her brother-in-law. Thus, the sages did not wish to answer “Amen” to a blessing which carried a dual, negative connotation.
From the fact that the Gemara goes to such lengths to explain why the sages did not answer “Amen” to her blessing, this proves that one should answer “Amen” to the blessing of another. Indeed, the Gemara (ibid. 66b) recounts that Nakdimon ben Gurion’s daughter and her husband arrived at the Bet Din in order to determine how much money she was entitled to for her fragrances and the sages of the Bet Din awarded her four-hundred gold coins. She exclaimed to the sages, “May it be Hashem’s will that you award the same to your daughters!” to which the sages replied, “Amen.” The Tosafot explain that here the sages decided to answer “Amen” since she was married and the entire blessing had a good and fitting connotation.
Based on the above, we can infer how bad it is when a congregation sits in the synagogue and does not pay attention and answer “Amen” to the “Misheberach” blessings given to one who has received an “Aliya” to the Torah and to those blessings recited by the rabbi or Chazzan to the members of the congregation when the Aron Kodesh is opened. Indeed, the issue here is that the reason why “Misheberach” blessings are so powerful and beneficial is due to the power of the entire congregation who answers “Amen” in a unified manner at such an auspicious time and in the merit of the Torah that stands before them. If the congregation does not answer “Amen,” the bulk of the benefit of this blessing is lost. It is quoted in the name of Hagaon Harav Shlomo Zalman Auerbach zt”l that one must answer “Amen” to a “Misheberach” blessing in fulfillment of the Mitzvah of loving one’s fellow like one’s self.