Intro to the riddle:
In the beginning of this week’s parsha, when Yaakov Avinu was already in Eisav’s eye view, the Torah says: “and he [Yaakov] prostrated himself to the ground seven times.” Why specifically seven times, and why does the Torah need to inform us of the specific number of bows that Yaakov Avinu did? Perhaps, the Torah is letting us know that by bowing seven times, Yaakov showed to Eisav that he is completely humbled in front of him, because number “7” signifies a complete unit—for example: 7 days of the week, 7 years in the Shmittah cycle, etc.
Riddle: There are many things that we do for Hashem in tefilla once each day (e.g., Pesukei Dezimra). There are also some things that we do for Hashem in tefilla twice each day (e.g., Krias Sh’ma). But what is something that we need to do for Hashem in tefilla at least seven times each day?!
