Naming after Tzadik or one’s Rebbe:

It is customary to name one’s children after the names of Tzaddikim, and for Chassidim to name their children after the name of their Rebbes.[1] [The same applies regarding girls, that they are to be named after righteous women.[2]]

Versus name of parent: Naming after one’s Rebbe may even have precedence over naming after one’s parent.[3] However, some Poskim[4] rule that naming after one’s parent takes precedence.

Not to add a name to the name of the Rebbe:[5] When naming a child after one of the Chabad Rabbeim, the Rebbe Rayatz was not fond of having another name added to it.[6] [For example, if one wouldlike to name his child after the Rebbe, he should only be named Menachem Mendel, and not have a third name added to his name.] This applies even if the added name corresponds to the name of a deceased relative. The child shall either be named completely by the name of the relative or only by the name of the Rebbe, and not with a mixture of both names. [Thus when naming a child after a deceased relative who had two names, and one of the names happens to be a name of one of the Rabbeim, one should not intend for the name to also be in memory of that Rebbe.[7] Nonetheless, on one occasion, the Rebbe instructed an individual who wanted to name his child after one of the Rabbeim, in contrast to his father’s wishes who wanted him to name the child after his grandfather, that out of Kibbud Av Vaeim he should listen to the request of his father, and he may then add whatever other name he wants to his grandfather’s name.[8] Hence, it seems that in times of need and for the purpose of Shalom Bayis the Rebbe suggested both allowing the grandfather to choose the name and to also add to the name of the Rabbeim, unlike that which was stated above.[9]]

Naming the child by only one of the names of the Rebbe:[10] If it is not possible for one to name a child after the full name of the Rebbe, such as if one of the names is already taken by a parent or sibling, then it suffices to name the child after one of the names. For example, one can name the child Yosef or Yitzchak after the Rebbe Rayatz, and it is not necessary to name him by both names. However, as stated previously, a second name which is not of the Rebbe should not be added to the name.

[1] See Shabbos 134a; Avos Derebbe Nasan 15; Zecher David 1:82; Noam Elimelech Parshas Bamidbar; Bnei Yissachar Kisleiv Mamar 4:121; Minchas Elazar 4:206; Otzer Habris 5:4-2; Nitei Gavriel 72:3; Sefer Hasichos 5703 p. 156 that the Mittler Rebbe was named after the Maggid; Sefer Hamamarim 5709 p. 90 that Reb Chaim Avraham was named after the son of the Maggid; Shevach Habris 20:6

The reason: Several reasons are mentioned behind this custom, including: 1) The name will have a positive effect on the child and influence it in a positive way. [Zecher David ibid] 2) The light of the Tzaddik that one is named after shines upon him and causes that he too be a Tzaddik [Noam Elimelech ibid; See Sefer Hamamarim 5709 p. 90 in name of Alter Rebbe] 3) It gives the child success in his Torah learning and motivates him to try to live up to his name. [Minchas Elazar ibid]

[2] Nitei Gavriel 72:7

[3] See Sefer Hamamarim 5709 p. 90 in name of Alter Rebbe

[4] Mishneh Halachos 6:252; Chemdas Tzevi 5:44; Az Nidbaru 13; Nitei Gavriel 72:4

[5] Igros Kodesh 12:215; 185; Igros Kodesh Rayatz 9:214; Album Yimei Bereishis p. 100 [from a private audience that an individual had with the rebbe in 1950, in which he was told he should not have named his son Menachem Yitzchak, having in mind both the Rebbe Rayatz and the custom of calling a child who is being circumcised on Tisha b’Av by the name Menachem, as one should not mix the names together]; Shulchan Menachem 5:159-160; Hiskashrus 356:19

[6] The reason: The reason for this is because the added name makes the entire name be considered a new name, and it is hence not considered that one is naming the child after the individual who has only one of the names. [Igros Kodesh 12:185; Tzemach Tzedek E.H. 153 end of Vol. 1] Likewise, one should not mix a holy name with a mundane name. [Igros Kodesh Rayatz 9:214]

[7] Hiskashrus ibid in the proper interpretation of the letter of the Rebbe Rayatz who answered an individual who had asked this exact question.

[8] Neilcha Beorchosav p. 235, brought in Shulchan Menachem 5:160; Hiskashrus 356:19

[9] Hiskashrus ibid

[10] Album Yimei Bereishis p. 100, brought in Shulchan Menachem 5:160 footnote 31; Kefar Chabad Gilyon 712:13; Hiskashrus 356:19 that this was done by many people under the auspices of the Rebbe; Shevach Habris 20:7