In the Mi Shebeirach (prayer for the sick), one should mention the sick person’s name and not his nickname, unless one does not know his name.
Sources and Explanations
The Gaon Rabbi Shlomo Zalman Auerbach (Halichot Shlomo, chapter 8, halacha 17) wrote that in praying for a sick person one should mention his name, as well as his mother’s name, and not the nickname. He therefore added (ibid., in the notes) that if the nickname is not a shortened form of the name but an entirely different appellation, the sick person should not be mentioned by that name but by his primary name. When Tehillim are said by the tzibbur for the merit of the sick person’s recovery, they should be careful to announce his name before they begin praying, so that the tzibbur will direct their prayers toward him. His students wrote there that the Rav instructed in Yeshivat Kol Torah that only in this manner is there the merit of the prayer of the many on behalf of the sick person. He also urged that those who lead the prayers be careful afterward to say the ‘Mi Shebeirach’ prayer aloud, and that the entire tzibbur wait until its conclusion to answer Amen after it, as was already explained in another note. Regarding the law of mentioning the sick person’s name, the book Tefillah KeHilchatah (chapter 12, halacha 42) wrote in the name of Rabbi Yisrael Yaakov Fisher that if one does not know his name, one may mention him by his nickname, even in a foreign language. If the sick person is an adopted son, he should be mentioned by the name of his adoptive mother (Orchot Rabbeinu, vol. 1, p. 64).
However, all this applies when one prays not in the presence of the sick person; but if the sick person is before him, it is preferable not to mention his name at all, as the Ben Ish Chai wrote in his book Ben Yehoyada (Ta’anit 25), that we learn this from the prayer of Moshe, may peace be upon him, for his sister Miriam, in which he did not mention her name and only said, ‘Please, Hashem, please heal her,’ since she was before him.
The Ben Yehoyada further wrote (Berachot 34, cited in Yabia Omer ibid.) that when one prays for his fellow to draw good upon him, it is good to mention his name; but for a sick person, to remove the illness from him, it is better not to mention his name, as in the case of Miriam. The reason it is preferable not to mention his name is that we are concerned that perhaps the name caused the illness (Iyun Yaakov, Berachot 34), for it is for this reason that some change the sick person’s name (see Rosh Hashanah 16b and Yoreh De’ah 335:10), and in Sefer Chassidim (siman 244) it is brought that the name causes good or bad.
From the sefer “Shaf Veyativ – Laws of Saying Tehillim” by Rabbi Shay Tahan, Chapter 9: Saying Tehillim for the Sick, Halacha 5 (p. 139 in the print edition). Translated from the Hebrew original.
