Responsum: On Kiddush
Question: Now about your inquiry concerning a congregation that recited the evening service and the Shema‘ before the appearance of the stars and no one could prevent them doing so, because at certain particular periods, several communities, of their own initiative, adopted a lenient stance in this matter, and recited the evening service prior to the appearance of the stars, which of these is preferable—for an individual to recite the Eighteen Benedictions [of the Amidah] together with the congregation, on account of the consideration that in the multitude of people lies the glory of the King (Proverbs 14:28), and leave over the recitation of the Shema‘ with its accompanying preceding and succeeding blessings until the appearance of the stars? Or to defer [the entire evening prayer] altogether until the appearance of the stars, and then recite the evening service in private, setting the [reference to] the redemption [from Egyptian bondage] in direct juxtaposition to the Amidah, in accordance with R. Yoḥanan?
Answer: The rabbis of the land of Israel used to do as follows. They recited [the Amidah] of the evening service in advance and subsequently recited the Shema‘ at its correct time; and they were not concerned with juxtaposing the redemption to the Amidah in the evening service. And we too view the matter in the same way, namely that reciting the Shema‘ at its correct time is preferable, and a convenient way of noting the correct time [for this] is the appearance of the stars. And [the timely recital of the Shema‘] is a Torah-based obligation and is thus more important than placing the reference to the redemption in direct juxtaposition to the Amidah, where it is not possible. And if an individual sees fit to recite the evening service first, [along with the congregation], that is perfectly in order, because praying together with the congregation is optional, whereas the second matter [i.e., the timely recital of the Shema‘] constitutes an absolute obligation.
Published in: The Posen Library of Jewish Culture and Civilization, vol. 3: Encountering Christianity and Islam.