ברכות א:ה פירוש: ברטנורא והסבר באנגלית

מזכירין יציאת מצרים בלילות – The section of Tzizit (Ritual Fringes – the third paragraph of the Shema: Numbers 15:37-41) is said during the Recitation of the Shema at night, and even though the night time is not the time [for the wearing of] Tzizit, as it says, “look at it (and recall all the commandments of the LORD and observe them…)” to the exclusion of nighttime clothing, we recite it (Numbers 15:37-41) at night because of [the mention of] the Exodus of Egypt which is in it.

Introduction In Eretz Yisrael during the time of the Mishnah people did not recite the third paragraph of Shema at night. This is the paragraph that talks about the tzitzit and about the Exodus from Egypt. The reason why it was not recited at night was that tzitzit, the central topic of the paragraph, are not worn at night. Our mishnah teaches that although the paragraph itself is not recited, the blessing after the Shema still makes mention of the Exodus.

כבן שבעים שנה – as I appeared old and not actually old, but because [the locks of] his hair had turned white on the day when he was appointed to be the Nasi/head of [the Sanhedrin] in order that he would look “old” and appropriate for the “presidency.” And on that self-same day, Ben Zoma expounded upon this Biblical verse.