Shemot (16:6), “And Moses and Aharon said to all of the children of Israel, in the evening you shall know that HaShem has taken you out of the land of Egypt. (16:7) And in the morning you will see the honor of HaShem…. (16:8) And Moses said, when, in the evening, HaShem gives you meat to eat and bread in the morning to be satisfied….” The meat, at night, would show them that HaShem took them out of Egypt. The bread, in the morning, would show them the honor of HaShem.
Bamidbar (11:5), “We remember the fish that we ate in Egypt for free”—from mitzvot (Rashi). Bnei Israel did not see the value and opportunity of keeping HaShem’s commandments. They felt that HaShem took them out of the burden of Egypt in order to burden them with His demands. This issue is addressed in two ways.
The first idea is that HaShem had no intention to burden them in the negative sense. “In the evening you shall know that HaShem has taken you out of the land of Egypt.” Their burden was over. The meat they ate at night had no commandments attached to it. HaShem had set them free.
“And in the morning you shall see the honor of HaShem.” The manna they ate in the morning did have commandments. They were not allowed to leave over of it until morning, and they were not allowed to search for it on Shabbat. And Shemot (16:4) states, “And HaShem said to Moses, behold I shall rain down for you bread from the heaven, and the nation will go out and gather it day by day, so that I can test them whether they will walk in My Torah or not.” Rashi explains that HaShem tested them by seeing if they would keep its commandments.
Once they realized, at night, that they were free, they would, in the morning, see the honor of HaShem—that it is an honor to serve HaShem and that He gave them the mitzvot for their benefit. And Devarim (8:3) states, “And he fed you the manna that you did not know nor did your fathers know, in order to let you know that not by bread alone does man live, but by all that emanates from the mouth of HaShem does man live.” And Devarim (8:16) states, “He fed you manna in the desert that your fathers did not know, in order to afflict you and in order to test you, to do good for you in your end.”