Translation:Shulchan Aruch/Orach Chaim/27
27: The Place and the Manner in which They are Put On.
1 The location where they are put on: That of the hand – is on the left arm on the bicep that is on the bone between the elbow and the armpit, and one should tilt the tefillin a little bit towards the side of the body in a manner when he bends his arm downward, it will be opposite his heart, and he will thereby fulfil "And these words should be on your heart". Gloss: It is necessary to place it at the top of the bone that is close to the elbow, but not in the half of the bone that is close to the armpit [SM"K]. [An amputee that does not have a hand, but only an arm, should put on without a blessing] [Tosfot, chapter Hakometz, wrote that an amputee is obligated and in the Or Zarua he wrote that he's exempt].
2
The right custom is that the "yud" of the Shel yad knot should be pointed to the heart, and the tefillin above it, facing the outer side. One should take care that the "yud" knot not to move from the tefillin.
3
The correct custom is to affix it that the ma'abarta, that the strap passes through it, should be placed toward the side of the shoulder, and the box toward the side of the hand.
4 One should not have any object blocking the tefillin and his skin, whether it is the shel yad or shel rosh. Gloss: And this is referring to tefillin but with the straps one does not need to be careful. [Rabbi Shlomo ben Aderet in Responsum Chapter 827].
5 A man who is prone to n'zilut, and if he needed to place the tefillin of the head on his flesh he wouldn't be able to place them at all, one can permit him to place the tefillin of the head on a thin hat that's near the head and should cover them because of the onlookers. Gloss: And those who place in this way should not make a blessing on that of the head, but should make a blessing on that of the hand, "to place" [according to the opinion of Rashba].
6 And a lefty, if he does all his work with his left hand, puts it on his "left hand" which is the right hand of all people. And if he uses both hands, he places them on the left of all people. And if he writes with his right hand and does all other work with his left hand, or writes with his left hand and does all other work with his right hand, there are those who say that he should put tefillin on his weaker hand because we need the "weaker hand." And there are those that say that the hand with which he writes is considered the right hand for this matter and he puts tefillin on the other hand. Gloss: [That is the practice].
7 Even though a man has a wound in the place where the tefillin rests, he should put on tefillin because there is space on the arm to place two tefillin, because from the middle of the bone that's close to the armpit until the elbow, is the place to put on tefillin.
8 The length of the strap of that of the hand should be enough in order to encircle the arm, and tie the knot from it, and stretch it over the middle finger, and wrap it around his finger three times, and tie it. And the global custom is to wrap it around the arm six or seven times.
Gloss: And one should not wrap the strap upon the titura in order to strengthen it on the hand (Rabbi Yaakov Levi).
9 The correct placement of the tefillin shel rosh is from the beginning of the hairline by the forehead until the end of the soft spot of a baby’s head.
10 The knot in the back of the head must be above in the nape. One must adjust the capsule that it should be in the middle in order that it should be between the eyes; and the knot should also be in the middle of the nape, and it should not tilt to here or to there. And the place of the knot that looks like a Dalet must be to the outside. Gloss: And the same rule applies regarding the knot of the hand, that one must be careful that it should not be twisted around [Mordecai, page 96].
11 The black side of the straps must be to the outside, and they should not be twisted around, regarding both that of the hand and that of the head. One should role down the straps so that they should hang down in front of him and they should reach the navel or a little above it. The width of the straps of that of the hand and that of the head should be at least as the length of a barley grain. If the length and width of the straps were less than the required measurement, if he does not find others, he puts them on the way they are until he will find others that meet the measurement. It is good that the tefillin of the head should be revealed and visible but it is not manners for a student to reveal tefillin in front of his rabbi. Gloss: And regarding that of the hand, one must not insist that they should be either revealed or covered [Mordecai, ibid.]. And it seems to me that now, that they are only put on during the time of reading the Shema and prayer, even a student in front of his rabbi can reveal even that of the head. And so is the custom not to be cautious. [His own words].