הלכה על אבות 2:4

And so [too,] that which they said (Bava Batra 21b) that the community in each and every place is obligated to set up teachers of infants, that a city that does not have infants of the house of their teacher will be destroyed and that [up to] twenty-five infants are set up with one teacher. And [also] that which they said (Avot 2:4) that a person not say, "When I will be available I will study [Torah]," lest he never become available - as a person does not know what a day will bring. As one's involvement in the world renews itself each day and pushes a man from one thing to another and from one bother to another; and [so] it will come out that all of his days will pass in bewilderment if he does not make himself available regardless and push himself to involvement [with] Torah [study]. But anyone who does this and desires blessing will be helped from the Heavens and the bewildering bothers of the world will be lightened from upon him, and the yoke of [other] creatures will be removed from upon him. And [so] he will dwell happily in this world all of his days, and it will be good for him in the world to come. And happy is the one who speaks to a listening year. [These] and the rest of its details are elucidated in Kiddushin in the first chapter and in dispersed places in the Talmud (see Tur, Yoreh Deah 246).