(mochorath, or mochoratham, "the morrow," or "tomorrow," "the day following"; mochorath ha-shabbath, "the day after the Sabbath," i.e. the first day of the week): The first day of the week was designated for the formal offering of the first-fruits in the form of wave-sheaves (Le 23:11), and of the wave-loaves 50 days later (Le 23:16-17). This recognition of an after-Sabbath during festive periods has its counterpart in the later ecclesiastical practice of celebrating not only Easter Sunday, but also Easter Monday, etc., and undoubtedly was a factor in establishing the custom which transferred the sanctity of the Sabbath to the first day of the week after the resurrection of our Lord.
Frank E. Hirsch