ושני תמימם שנה בני כבשים שני השבת וביום” (ט כח) “ונסכו בשמן בלולה מנחה סלת עשרנים
The Rema (Orach Chaim 281 1) rules: “And it is customary that on Shabbos we come a bit later to shul than during the week, because the Tamid of the weekdays says “baboker” (Bamidbar 28:4) and on Shabbos it says “ubeyom haShabbos” (Bamidbar 28:9) which indicates a lateness.” But the Ba”ch (on the Tur, ibid) notes that the word “ubeyom” applies to the Korban Mussaf and not the Korban Tamid, so how can we learn from it about Tefillas Shacharis – corresponding to the Tamid – being late?
Harav Pinchas Halevi Horowitz, the Rav of Frankfurt, explained that although the word “ubeyom” applies to the Korban Mussaf, it still indicates a later time for getting up on Shabbos, and therefore, a later time for Shacharis. Because Chazal learn from this word (see Rashi Pesachim 58a, ad loc. Rabbi Yishma’el) that the time for sacrificing the Mussaf was from the sixth hour in the day, and the same is for Tefillas Mussaf that corresponds to it. So because a person cannot eat before Mussaf (Shulchan Aruch Orach Chaim 286 3), and on the other hand, a person must not fast on Shabbos later than six hours from when he rises (ibid 288 1; Magen Avraham 157 1), therefore, it is customary to rise later on Shabbos so that the person can daven Mussaf in the sixth hour without having had six hours pass from the time he wakes up until he returns home to make Kiddush and eat.
Panim Yafos
