The Gemara in Masechet Pesachim (105) discusses the case of a person who enjoys a particular food but has enough only for one of the Shabbat meals. Should he eat this favorite food during the Friday night meal, or should he save it for Shabbat day?
The Gemara rules that "Kevod Ha'yom Adif" the honor of the day of Shabbat takes precedence over the night of Shabbat. Therefore, if one has a limited amount of his favorite food, he should save it for the meal on Shabbat day, rather than eat it already during the meal on Friday night.
