Mentioning the mother's name in the tefillah for a sick person

[א] (halacha 4)

Question: When mentioning a person for a recovery, does one mention his father's name or his mother's name?

Answer: When praying for a sick person or when making a 'Mi Shebeirach,' there are those who have the custom to mention the sick person in the Mi Shebeirach together with his father's name. However, our minhag (Igros Kodesh vol. 8 p. 281) is that in matters of health — whether physical or spiritual — one mentions specifically the mother's name of the sick person, and this is based on the holy Zohar in Parshas Lech Lecha (folio 84a) that when a person wishes to receive some lofty thing — meaning that his request should be remembered above — he must mention his mother, and therefore Dovid HaMelech prayed and said "אני עבדך בן אמתך" ("I am Your servant, the son of Your maidservant"). And there is also an allusion to this in the Gemara in Maseches Shabbos (folio 66b). And these are the holy words of the Rebbe (in Igros Kodesh vol. 9 p. 33): 'One who has knowledge of the customs of the chassidim in writing to their Rebbe knows that quite frequently they sign with the addition of the mother's name, even in letters and not specifically in a pidyon nefesh. And therefore it is worthwhile to be particular in tefillah for a sick person and in a Mi Shebeirach to say specifically with the mother's name.'

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