The Gemara describes a group of people called "Tayalim" (men of leisure). Rav explains that this term refers to persons like Rav Shmuel bar Sheilas, who "has enough to eat from his own, has enough to drink from his own, and he sleeps in the shade of his palace, and [because he is not overly wealthy] he does not attract the attention of the king's servants."

The HAFLA'AH explains that Rav Shmuel bar Sheilas merited this special treatment because of his sincere Mesirus Nefesh for teaching Torah.

In Bava Basra (21a), Rav praises Rav Shmuel bar Sheilas as a responsible teacher of Torah to young children. The SHULCHAN ARUCH (YD 245:17) says that a person who teaches Torah to children is not permitted to do any other work. The REMA adds that he is not allowed to stay up late at night, to refrain from providing his body with nourishment, or to eat or drink too much, because he might become too tired or too hungry to teach properly. Since Rav Shmuel bar Sheilas strove to teach the children in the best possible way he could, he merited Divine assistance that he had enough to eat and drink, he was relaxed and not tired or pressured, and the king's men did not bother him and distract him, and thus he was able to concentrate his attention and efforts on his important task.

QUESTION: The Gemara records stories about Tana'im and Amora'im who left their homes to learn Torah for twelve years after their marriage. What is unique about the period of twelve years, such that all of the Tana'im and Amora'im mentioned left home to learn specifically for that amount of time?

(a) The MAHARSHA explains that the Mishnah in Avos (5:21) states that a person is enjoined to get married at the age of eighteen, and the peak of his strength is at age thirty. Since a person learns best after he is married (Yevamos 62b), the best time to set aside for learning Torah are the twelve years between eighteen and thirty.

(b) The CHIDA (in Sefer Mar'is ha'Ayin) writes that there are (approximately) 613 weeks in twelve years. When one spends twelve uninterrupted years in Torah study, he is able to spend one week learning each Mitzvah.

(c) The BEN YEHOYADA adds that the twelve years of learning are comprised of six years during which one learns the six Sedarim of Mishnah and Gemara with breadth (b'Ki'us), and six years of during which he delves deeply into the six Sedarim (b'Iyun).

He adds that there is an allusion in a verse that success in learning comes after a person has learned for twelve years. The verse states, "For six years you shall sow your field and for six years you shall harvest your vineyard, and you will gather the produce" (Vayikra 25:3). "For six years you shall sow your field" -- just as sowing a field prepares the way for growing fruits, one must spend six years preparing the way for understanding the Torah by learning the breadth of Torah. "And for six years you shall harvest your vineyard" -- these are the six years of delving into the Torah in depth and arriving at Halachic conclusions in one's learning. After that, "you will gather the produce." "The produce" refers to the Torah (Bava Basra 145b), for after twelve years of learning one will have made a genuine acquisition of Torah learning.