The halakhic ruling: Were the prayers instituted by the patriarchs or based on the daily offerings? Since the Talmud does not present this as a clear-cut dispute, some halakhic authorities are inclined toward the opinion that the prayers were instituted to correspond to the daily offerings. Therefore, matters relevant to the laws of the offerings apply to prayer as well, e.g., the obligation to pray in a fixed place, just as offerings were brought in the Temple; and the fact that an improper thought can invalidate a prayer, just as it can invalidate an offering (see Tur, Oraĥ Ĥayim 98). The Rambam, too, presents the times of the prayers as corresponding to the offerings (Mishneh Torah Sefer Ahava, Hilkhot Tefilla 1:4), although elsewhere he states that the prayers were instituted by the patriarchs (Mishneh Torah, Sefer Shofetim, Hilkhot Melakhim 9:7). Some explain that the Rambam rules in accordance with the opinion that the structure of the prayers was fixed parallel to the offerings (Kesef Mishneh), while others explain that he holds there is no dispute between the Sages with regard to this point (Leĥem Mishneh). The authorities also discuss possible practical differences between these opinions. For example, may one recite a voluntary prayer at his own initiative however he wishes, or whether even a voluntary prayer, too, must be recited in accordance with the principles governing a gift offering in the Temple.