1. When a woman goes to the mikvah, she must take great care about the presence of any chatzitza (intervening substance) on her skin. Must a man take equal care about this matter when he is wearing tefillin?
Although failure to properly perform the mitzvah of tefillin is not as serious as invalid immersion, great care still must be taken that there is no intervening substance between the tefillin's boxes or straps and wearer's body. Even if the chatzitza is small and its presence does not bother him, the boxes and straps must have direct contact with his body (as the garments of the kohanim must rest directly upon the kohen himself).
2. What are some common examples of a chatzitza?
- Pompadour hair is a chatzitza (Mishnah Berurah 27:15), as is the hair of payos if, instead of hanging down naturally, it is pulled upwards. Some are stringent regarding any long hair.
- Serious, very recognizable dandruff (Tefilla L'Shma 12:2).
- Lice, even a live one (Mishnah Berurah 27:14).
- Water in significant quantity, and so, too, perspiration (such as on one's forehead).
- Dried perspiration that is stuck to the undersides of the tefillin's base (Orchos Chaim 27:3).
- Cut hair (e.g. after a visit to the barber) if one is bothered by its presence.
- On the underside of the base of each tefillin, remnants of paint, if they easily can be scraped off and beforehand can be felt. A scribble of ink from a pen is not a chatzitza (Shulchan Aruch, Yoreh Deah 198:17).
3. Is one allowed to wear tefillin over a bandage or over the sleeve of one's shirt?
Over one's sleeve it is not permitted (Mishnah Berurah 27:18).
Over a bandage or cast it is permitted, because these things they are considered more as if they are a part of his body. Still, he should say the blessing "ahl mitzvos" on the tefillin that will not rest upon the bandage or cast, and have in mind to include both tefillin in the blessing (Minchas Yitzchak, Chelek 2:46). Afterwards, he should cover the tefillin that are over the bandage or cast, so that onlookers will not get the wrong idea (Shulchan Aruch, Orach Chaim 27).
4. Regarding the tefillin of the head, is it essential to exactly center them on the forehead?
One can center them as best one can, using one's hands and fingers, without the help of a mirror (Divrei Chaim, Chelek 2:6).
5. Due to the prohibition on men do look at themselves in mirrors, is it better to not don the tefillin of the head with the help of a mirror?
One need not be stringent, because today, the law of mirrors is different from in days gone by. Looking in a mirror no longer is considered a practice appropriate only for women. A mirror no longer is considered womanly "ornamentation," and if a man uses a mirror, particularly for the sake of a mitzvah, it is not regarded as if he is wearing women's clothing (R. Yosef Shalom Eliashiv, VaYishmah Moshe, 35).
6. If one puts on his tefillin on a place where there is a chatzitza (e.g. he put them on over his sleeve) does he need to put them on again with a beracha?
No. He should simply remove the chatzitza (Responsa of Har Zvi, Chelek 1:23).
7. If the knot of the tefillin is tied with the dark side of the strap facing inwards instead of outwards, what is the halacha?
He did not fulfill the mitzvah. The knot must be tied correctly and then he must put the tefillin on a second time, with the blessing. (Shulchan Aruch, Orach Chaim 27:11).
8. Should the knot of the tefillin of the arm be tied so it rests on the side of the box that is towards one's heart, or should it be found on the opposite side of the box?
It must be on the side towards one's heart (Shulchan Aruch, Orach Chaim 27:1).
Therefore, if one's practice is to wrap the strap outwards -- away from himself -- as he wraps it around his arm (the Sephardic custom), if it happens that one day he has only arm tefillin whose strap is wrapped on the arm in the opposite direction (inwards, towards the person, as is the custom of Ashkenaim), he must not turn the entire tefillin upside-down on his arm to enable himself to wrap the strap in the direction that is normal for him, because if he does, no longer will the knot be facing his heart.
If it happens that someone who is left-handed must wear regular (right-handed) tefillin, he must turn the box around so the knot is on the side of the box that faces his heart (Biur Halacha, Shulchan Aruch, Orach Chaim 27:10).
9. Must the knot of the arm tefillin be touching the box?
The Zohar is very particular that yes, it must. However, if the knot was not touching there is no need to put on the tefillin a second time with the knot touching. The custom is to tie the knot to the box by means of the same type of thread that is used to make the tefllin themselves ("gid"), but any type of thread or string can be used, and even a rubber band. Some want the knot touching but have the stringency of not tying it to the box (Chazon Ish).
10. Does one need to remove the protective covering from the tefillin of the arm?
It is proper that it not be there when one says the blessing (Shevet HaLevi, Chelek 8:5).
11. If a person does not know how to put on tefillin, what should he do?
He should ask someone else to put them on him, even if that person is himself exempt from the mitzvah -- such as a minor or a gentile (Mishnah Berurah 27:106). One recites the blessing after they are on, and one is allowed to say the blessing even if the tefillin have been on him for a long while.
12. If someone is unconscious or sleeping, should someone else put tefillin on him?
No (Shevet HaKehati 4:24).
13. If two men are approaching the door of the beis ha-knesses and one is wearing a tallis and tefillin, while the other is carrying tefillin, should one enter before the other, in deference to the mitzvah of tefillin?
Yes, the one who is carrying tefillin should enter first, because when a man is wearing tefillin, it is as if they are a part his body itself. They are "nullified" relative to his body, so were he honored to enter first, the honor would be going to him and not to the tefillin! So that honor and deference be afforded to the tefillin, the one carrying them should be given the privilege of entering first (Piskei Teshuva 157, in the name of R. Yosef Dov Soloveitchik of Brisk. However, the Responsa Evin Yisroel [Chelek 8:5] disputes this ruling, giving precedence to the one wearing the tefillin, for he, as opposed to his fellow, presently is fulfilling the mitzvah).
14. How does one position his tefillin when he puts them away in their bag?
The custom is to put the tefillin of the head into the right side of the bag and the tefillin of the arm to their left. (Aruch HaShulchan 25:19).
15. Can one keep one's siddur in one's tefillin bag?
It is permitted only if one stipulated as such when he purchased the bag. (Shulchan Aruch, Orach Chaim 42:3)
Today, since the custom is that each of the tefillin is stored in its own snugly fitting plastic casing, one can be lenient and place one's siddur in one's tefillin bag without the prior stipulation that he intended to do so.
16. What is to be done if the tefllin fall to the ground?
If they were not in the hard, casing (with the hinge) in which they are stored, the custom is to fast. Some say that instead of fasting, one can significantly increase one's Torah learning for one day, or one can give tzedaka – enough to pay for a meal for a poor person.