The discussion of ma’aseh bereishit – the secrets of creation – continues with a description of the heavens. The Gemara records that Rabbi Yehuda recognizes two heavens, while Reish Lakish enumerates seven heavens. (It should be noted that Rav Yehezkel Landau explains in his Tziyyon le-Nefesh Hayyah that the heavens referred to here are spiritual ones, rather than physical ones.) Rav Aha bar Ya’akov argues, based on the passage in Yehezkel 1:22, that there is another heaven that stands above these. Nevertheless, this highest heaven cannot be discussed, because of the saying that appears in Sefer Ben Sira: “Seek not things concealed from you, nor search those hidden from you. Reflect on that which is permitted to you; you have no business with secret matters.”
Sefer Ben Sira is one of the earliest books composed after the closing of the Biblical canon. It was authored by Shimon ben Yehoshua ben Sira, a native of Jerusalem, who was a younger contemporary of Shimon HaTzaddik, prior to the Hasmonean era. The book of Ben Sira was held in great esteem, and after its translation into Greek by the author’s grandson (in the year 132 BCE in Alexandria) it because widely known even among those who were not familiar with the Hebrew language. Sefer Ben Sira is included as a canonical work in the Septuagint (and therefore is considered such in many other translations of the Bible), and although the Sages chose to view it as one of the sefarim hitzoni’im – books outside of the canon – they quote it in a respectful manner throughout the Talmud, sometimes even referring to it as ketuvim. Still, because of confusion between this work and another one that was known as Alfa-Beta d’Ben Sira, which was a popular – and problematic – work, we find statements in the Gemara forbidding the study of Sefer Ben Sira.
The quote from Sefer Ben-Sira that appears in our Gemara can be found (with minor changes) in chapter 3, passages 21-22.