מצות עשה על האיש ללמד את בנו תורה ואם לא למדו אביו חייב ללמד לעצמו (וע"ל סי' רמ"ג סעיף ו'):

The Laws of Teaching Children Torah. It is a positive commandment for a man to teach his son Torah. And if his father did not teach him, he is obligated to teach himself. And see Siman 246:6.

If he himself needs to learn, and he has a son to teach, and he does not have the means to provide for both of them, if they are equal [in intellect], he precedes his son. But if his son is perceptive and comprehends what he learns more than he [the father] does, his son precedes him. Nevertheless, he should not neglect [his own studies]

Just as it is a mitzvah to teach one's son, so too it is a mitzvah to teach one's grandson, as it is stated: "And you shall make them known to your children and your children's children" (Devarim 4:9). And not only one's grandson, but it is a mitzvah upon every wise man in Israel to teach students, for they too are called "children." However, it is a mitzvah to give precedence to one's son over one's grandson, and one's grandson over the son of one's fellow.

One is obligated to hire a teacher (melamed) for his son, to teach him. But for the son of his fellow, he is not obligated to hire [a teacher]. Rema: And they compel him to hire a teacher for his son. And if he is not in the city, and he has assets, if it is possible to inform him, they inform him; and if not, they take possession of his assets and hire a teacher for his son. (Hagahos Maimoni, Chapter 1 of Hilchos Talmud Torah, in the name of Maimonides).

From when does one begin to teach his son? From the time he begins to speak, he begins to teach him, "Torah Tziva Lanu Moshe..." (Torah was commanded to us by Moshe…) (Devarim 33:4), and the first verse of the Shema (Devarim 6:4), and afterward he teaches him little by little, until he is six or seven years old, and then he takes him to a teacher of children (melamed tinokos).

If it was the custom in the city that the teacher of children takes a fee, he is obligated to teach him for a fee until he reads the entire Written Torah (Torah Shebichsav). And he is not obligated to teach him, for a fee, Mishnah and Gemara (Talmud). And this only applies when it is not possible, for he is hard-pressed for time, but if it is possible for him, it is a mitzvah to teach him Mishnah and Gemara, Halachos, and Aggados.

They establish teachers of children in every city. And any city that does not have a teacher of children, they excommunicate the people of the city until they establish a teacher of children. And if they did not establish [one], they destroy the city, for the world only exists because of the breath of the mouths of children in the schoolhouse. And see Choshen Mishpat Siman 163:3.

Children are brought in to learn at five full years of age, and fewer than that they are not brought in. And if he is weak, he is brought in at six full years of age. Rema: And nonetheless, immediately when he is three full years of age, they teach him the letters of the Torah, so that he will accustom himself to read in the Torah. (The Rav Abarbanel (Rabbi Don Yitzchak ben Yehudah Abarbanel) in his commentary to Avos).

Even a child who does not understand how to read, they should not remove him from there but he should sit with the others; perhaps he will understand.

The teacher should not strike him a blow of an enemy, cruel discipline, not with whips and not with a stick, but rather with a small strap.

He sits and teaches them all day and a bit of the night, in order to train them to learn during the day and at night.

They do not dismiss the children at all, except on Erev Shabbos and Erev Yom Tov at the end of the day.

They do not dismiss the children, even for the building of the Temple.

The children are not to read on Shabbos for the first time, something that they did not learn, due to the exertion of Shabbos. But what they read once, they may repeat it to them on Shabbos.

Twenty-five children suffice for one teacher. If there were more than twenty-five, up to forty, another is appointed to assist him in their instruction. Rema: And even if the community hired a teacher for all the children without specification, he appoints another to assist at their expense, and they give him his fee. (Nimukei Yosef, Perek Lo Yachpor). And some say that if there are not twenty-five children in the city, the people of the city are not obligated to hire a teacher for them. (Hagahos Maimoni, Chapter 2 of Hilchos Talmud Torah, and Tosafos (The Medieval commentaries on the Talmud) and Rabbi Yerucham). And some say that even with fewer than this, they are obligated. (Ibid. in Nimukei Yosef). If there were more than forty, two are appointed.

They take the child from one teacher to another teacher who is quicker than he, whether in Scripture (Mikra) or in grammar (dikduk). In what case is this said? When both of them were in one city and there is no river separating them. But from city to city, or from one side of the river to the other side in the same city, he is not taken, unless there was a bridge, a sound structure, that is not likely to fall quickly.

A teacher of children who leaves the children and goes out, or who does other work with them, or who is lax in his teaching, he is included in the statement: "Cursed is he who does the work of Hashem deceitfully" (Yirmiyahu 48:10). Therefore, a teacher should not be appointed unless he is G-d fearing, quick to read, and precise in teaching. Rema: And a teacher should not stay up too late at night, so that he will not be lazy during the day to teach. And similarly, he should not fast, or abstain from food and drink, or eat and drink excessively, for all these things cause him not to be able to teach properly. And anyone who deviates, his hand is on the bottom and he is dismissed. Mordechai, Perek Ha'umanin from the Yerushalmi (The Jerusalem Talmud). And the rest of the laws of a teacher, see in Choshen Hamishpat Siman 334 and 335.

If there is a teacher here who teaches children, and another comes who is better than he, they dismiss the first on account of the second.

If there are two teachers here, one reads a lot and is not precise with them to make them understand properly, and one does not read so much, but is precise with them to make them understand, they take the one who is more precise.

One who does not have a wife should not teach children, because their mothers bring their sons. And the teacher does not need his wife to be present with him in the schoolhouse, but rather she is in her house and he teaches in his place.

A woman should not teach children, because of their fathers who bring their sons.

One of the residents of a courtyard or the residents of an alleyway who sought to become a teacher of children, his neighbors cannot object to him. And similarly, a teacher of children whose colleague came and opened a house to teach children beside him, in order that other children should come to him or in order that the children who are with this one should come to that one, they cannot object to him, as it is stated: "Hashem desires, for the sake of His righteousness, that the Torah be made great and glorious" (Yeshayahu 42:21). Rema: A rabbi who sits in the city and teaches the masses, another sage can come and teach there as well, even if he somewhat cuts off the livelihood of the first, such as when the community accepted the first as their rabbi and takes a fee from them for this, even so, the second can come to reside there and to maintain authority in every matter, like the first, if he is great and fit for this. (Mahari"v, Siman 151 and Mahara"i in his Psakim, Siman 158, see there the responsa of the great ones). But if a visiting sage came to the city, he may not cut off the salary of the rabbi who resides there to perform weddings and to collect the fee that comes from them, since it is the salary of the resident rabbi; but he is permitted to perform the wedding and to give the fee to the established rabbi. And similarly, he is permitted to judge between two litigants in the city who come before him to judge, for perhaps the rabbi in the city is not suitable for them. But he may not teach matters of prohibition and permissibility, or to preach to act with authority, in the place of his fellow. (Mahari"k, Shoresh 170 and Mahar"d in a responsa 22). One who was established as a rabbi in the city, even if he established himself in some authority, he may not be removed from his greatness even though another came there who is greater than he.(Rivash, Siman 271). Even his son and his grandson forever precede others, as long as they fill the place of their fathers in piety and they are somewhat wise. (Rambam, Chapter 1 of Hilchos Melachim). And in a place where there is a custom to accept a rabbi for a set time, or that it is customary to choose whomever they desire, they have the authority, (Kol Bo). But anyone whom the community accepted upon themselves, and all the more so if they did so with the consent of the authority, no great one in the world may usurp authority over him and remove him. (Ibid. in Rivash).