Commentary for Kiddushin 59:9

אמר רב ספרא משום ר' יהושע בן חנניא מאי דכתיב (דברים ו, ז) ושננתם לבניך אל תקרי ושננתם אלא ושלשתם

R'Safra said on the authority of R'Joshua B'Hanania: What is meant by, and thou shalt teach them diligently [we-shinnantem] unto thy children?<span class="x" onmousemove="('comment',' Deut. VI, 7.');">¹⁶</span> Read not we-shinnantem, but we-shillashtem: [you shall divide into three]: one should always divide his years into three: [devoting] a third to Mikra, a third to Mishnah, and a third to Talmud. Does one then know how long he will live? - This refers only to days.<span class="x" onmousemove="('comment',' Rashi: two days in the week to Mikra, two to Mishnah, and two to Talmud. Tosaf., more plausibly: each day itself should be divided into three. - Actually, scholars have always confined themselves to Talmud: but as the Babylonian Talmud is an amalgam of the three, this dictum is held to be fulfilled; v. Sanh. 24a. Furthermore, the early part of the morning liturgy contains passages from all three.');">¹⁷</span> The early [scholars] were called soferim<span class="x" onmousemove="('comment',' Rashi quotes, and the families of scribes - Soferim - which dwelt at Jabez; I Chron. II, 55. The term is generally applied to the band of Scholars from the Babylonian exile, who propagated the knowledge of the Torah and interpreted it.');">¹⁸</span>

Daf Shevui to Kiddushin