You correctly pointed out
that when praying for someone in need, we utilize the mother's name.
Although tribal and familial affiliation within the Jewish people ("Are
you a Kohain or a Levi?"), are determined by the father's line,
it seems spiritual essence is transmitted through the mother.1
It is this essence which constitutes the Jew's unbreakable link to G-d.
Therefore, when Divine aid is sought in serious situations we identify
the person in our prayers as the offspring of a particular mother, instead
of the father.
Sometimes, when a person
without a Jewish name is called for an aliyah to the Torah, you may
hear a Hebrew name be given on the spot: Jack becomes Yaakov, etc. However,
there are significant distinctions between the use of names when praying
for someone and when calling to someone by name. In the latter case
the person is present, so strict accuracy is not necessary in calling
his name for it to be clear who is meant. Indeed, you can beckon to
someone, or even call him for an aliyah without even saying the name
In prayer, however, the person
being supplicated for is usually not there, so it is necessary to be
precise. More importantly, when speaking to G-d it is essential to be
truthful, and also as specific as possible. Therefore, if a person has
no Jewish name, or even if he has one but it is not known, the foreign-language
name should be used.2
When the mother's Hebrew
name is unknown, we may pray for the person as "ben" or "bat
Sarah". This is legitimate since we are all descendants of Abraham
and Sarah. If only a non-Jewish name is known for the mother, it may
be used (unless it is one with unpleasant connotations for Jews).
A formal religious ceremony
is not an absolute requirement in the giving of a Jewish name, although
it certainly can be an inspiring enhancement. While boys are usually
named during the circumcision ceremony and girls on the occasion of
a blessing over the Torah within a few days after the birth, a name
given by the parents in other circumstances is equally valid.
To change a Jewish name given
at birth by parents is a serious matter. Someone who desires to choose
a new name for himself is advised to get the approval of a tzaddik,
or at least a knowledgeable rabbi. In any case, the official ratification
of a new name or name-change automatically occurs when the person is
called by it for 30 days.
When a name change is advisable
for someone who is seriously ill, it is a common practice to add another
name to the existing one (and certainly to give a Hebrew name to a Jew
who doesn't yet have one). In such a case a minyan should definitely
be convened to recite the special name-changing prayer for people in
life-threatening situations (found in the back of many Tehillim books),
even if it is not being done in a shul.3
The importance of knowing
your given Jewish name cannot be over-estimated. It is said that on
the occasion of naming a new baby, parents are blessed with divine inspiration.
They need it! The Hebrew name of any person (or any created thing, for
that matter), is a reflection of the particular spiritual essence of
that being.4 A Jew who does not know his Jewish name or claims
not to have one should make every attempt to verify if there was a given
or intended Jewish name. For example, if his parents also don't know
or don't remember, he can ask his older relatives if he was named after
someone. A lot of "Lindas" are named after great-grandmother
"Leah," etc. In such cases you could say the Hebrew name is
the person's original, "real" name, since it preceded its
1. Perhaps this is why Jewish status at birth is determined by the
mother's Jewishness rather than the father's.
2. This is so even for those prayers where verses are said according
to the Hebrew spelling of the name. A responsa written 400 years ago
says that in Europe in an extreme situation they would pray for the
inhabitants of a city in danger by reciting verses according to the
letters of the name of the city. Presumably they weren't Hebrew names!
3. The prevalent custom today is to add the name Chaim ["life"],
Boruch ["blessed"] or Alter ["long-lived"]
before a male's name, or the feminine equivalent--Chaya, Bracha,
or Alta--for a female. There is also a custom to add a name of
a long-lived personage from Scripture. For a female, for example, you
might add Sarah or Yocheved, but not Rachel.
4. Tanya II, ch. 1.