Daf Yomi - Beitzah 22 - Lekavod Shabbos

The Gemara discusses a case where if one who did not make an eruvei tavshilin for himself, others can prepare food for him. Some say that that they can even roast small fish for him. What is the reason that we eat fish on Shabbos? In Siddur Abir Yaakov it is said that one reason why we eat fish on Shabbos is because when HaShem created the world, He bestowed three blessings. On the fifth day, HaShem blessed the fish. On the sixth day, HaShem blessed man. On the seventh day, HaShem blessed Shabbos. When we eat fish on Shabbos, we bring the three together. It is said in Koheles that something that is threefold cannot be broken easily. A second reason offered is that Shabbos provides us with a taste of the Messianic Era. At that time the righteous will be given a meal from the fish called leviasan. Eating fish on Shabbat reflects this idea. I have also heard that the word for fish is דג, which is in numerical value seven, and Shabbos is the seventh day of the week. Perhaps there is another idea regarding the eating of fish on Shabbos. It is known that the word Shabbos is an acrostic for the words שינה בשבת תענוג, sleep on Shabbos is a delight. Some people assume that one must sleep on Shabbos as much as possible. Yet, the halacha is that a Talmid Chacham who is engaged in Torah study all week can sleep more than usual on Shabbos. One who does not have the same opportunity to study Torah during the week, however, should sleep less on Shabbos and he should study more Torah. I heard Rabbi Nachum Lansky, Shlita, (Maggid Shiur in Ner Yisroel Baltimore) say that Yehoshua Ben Nun was thus called because a fish in Aramaic is a נון. Fish do not have eyelids, and Hashem instructed Yehoshua to study Torah day and night. Thus, we can suggest that we eat fish on Shabbos to demonstrate that since most Jews do not have the opportunity to study Torah all week, should at the least stay awake as much as possible on Shabbos and engage in Torah study.