Question: [Wednesday, 6th Kisleiv, 5782]
Many families have a tradition that a child should not look in the mirror prior to him growing teeth, and that you should not step over a child lest he not grow, and if you do step over him that you should step over him the other way. Is there any source for these traditions and am I obligated to follow them or are they forbidden to be followed?
These traditional superstitions do not have any known source in classic Jewish literature, and therefore are not obligatory to be followed. Nonetheless, being that these customs have traditionally been followed amongst God-fearing families throughout many generations, they therefore do not transgress any prohibition, and may be adapted if one wishes. While one without a family tradition in this matter is not obligated to follow these customs, he may do so if he wishes.
Those who have a family tradition to beware of these matters, should respect their family tradition. If a husband does not have the tradition while the wife does, or vice versa, then it is proper for the spouse without the tradition to follow them anyways for the sake of peace.
Explanation: Adapting superstitious practices that are not sourced in classic Jewish sources enters the question of the prohibition of Lo Sinacheish and Darkei Emori, and practically one needs to research whether they were traditionally practiced amongst God-fearing Jewish homes, in which case one does not have to worry of them containing any prohibition. Nonetheless, even if verified that the superstition has traditionally been followed by some Jewish families, it does not obligate everyone to adapt to these superstitions, and so can be argued that it is better to ignore it and not create unnecessary Ayin Haras. Now, regarding the specific superstition of not having a child look at the mirror and walking over a child, we find that it was traditionally practiced amongst God-fearing homes in Europe, and therefore there is no prohibition involved in following it. However, those who did not receive such a tradition may ignore it if they choose. Now, regarding if one who received such a tradition from his family if he may stop following it, this enters the question of breaking a family custom, although in my opinion it seems that one can choose to ignore it if it has no source in classic Jewish sources and is not a very widespread adherence that is kept. For extra insurance, he should do Hatars Nedarim.
Sources: See regarding holding baby to mirror: Beir Moshe 8:36; See regarding walking over child: Beir Moshe 8:36; Mishneh Halachos 13:119; Shemiras Haguf Vihanefesh 1 Mavo Chapter 16 p. 91; Imrei Shamaiy Vol. 2 p. 185; Viein Lanu Michshol 2 Chapter 7:3; Shulchan Aruch Hamekutzar 4 139:58 [that so was custom of Yemenite Jewry regarding walking over a child]; Darashta Vechakarta 5 C.M. 8:1; Sheilas Rav 1 21:8 and Sefer Asicha p. 400 in name of Rav Chaim Kanievsky that the custom of women is to be careful and that it is a Minhag Yisrael; Segulos Rabboseinu p. 369; Rav Meir Mazuz stated that the worry is nonsense and one who is not Makpid has nothing to worry about; Response of Rav Eli Landa Shlita: Rav Eli Landau responded to us regarding the above customs, that the adherence of not allowing a child to look at the mirror until a certain age was certainly followed in his home as well as the home of many Jewish families and is a traditional Jewish custom. However, the custom of not walking over a child he said was not as much widespread and he therefore questioned its status as Minhag Yisrael. Whatever the case, he stated that one without a family tradition in this matter has no obligation to adapt to these customs if they don’t want to, and it is simply a question of whether one is allowed to suspect for them, or should suspect for them due to his family tradition. See regarding the general Halachic issues with superstitious beliefs and if they may or should be follwoed: Michaber Y.D. 178-179; Rambam Avoda Zara 11; Sanhedrin 65a; Encyclopedia Talmudit Erech Darkei Haemori Vol. 7; Shiltei Hagiborim Avoda Zara 9a, brought in Pischeiy Teshuvah 179:3; See Yerushalmi Terumos 8:3 that one needs to suspect for that which people worry of danger; Sefer Chassidim 261 that there is danger involved in matters that people believe to be dangerous; Minchas Yitzchak 9:8; See regarding Hataras Nedarim: Michaber Y.D. 214:1-2