וְהָאסַפְסֻף אֲשֶׁר בְּקִרְבּוֹ הִתְאַוּוּ תַּאֲוָה וַיָּשֻׁבוּ וַיִּבְכּוּ גַּם בְּנֵי יִשְׂרָאֵל וַיֹּאמְרוּ מִי יַאֲכִלֵנוּ בָּשָׂר: זָכַרְנוּ אֶת הַדָּגָה אֲשֶׁר נֹאכַל בְּמִצְרַיִם חִנָּם ...The gatherers among them generated a craving, and the Children of Israel also wept again, and they said, “Who will feed us meat?” We remember the fish we ate in Egypt free of charge… (11:4-5)
These verses teach us that the Jewish People were not satisfied with the mannah they received; for even though it tasted of almost any flavor they could imagine, they nevertheless wanted real fish, even suggesting that they were better off in Egypt where it was sold to them for almost nothing.
This complaint is incredulous! Here, the Jewish People were being provided their needs yet they still complained that they would fare better elsewhere, relying on their own efforts as opposed to being sustained directly from Hashem.
The understanding that Hashem provides for all our needs wherever we are is a fundamental precept of emunah, faith in Hashem. The Chovos Halevovos says, “Someone who trusts in anything except for Hashem (either someone else, or his own wealth, or his wisdom and strength etc.) Hashem removes his providence from him and leaves him with that which he trusts.
One person whose life was saved by placing his trust in Hashem once met Rav Yaakov Galinsky. The man was from Vienna and was having difficulty in finding a livelihood; so, like many other Jews, he bought a ticket to travel to America to gain his fortune. Although he was not a chassid, his friends convinced him to receive a parting blessing from Rebbe Yisroel M’Tshorkov. After explaining why he was there, the Rebbe responded, “Aha! You’re going to America. Allow me to give you a spiritual remedy for protection. I want to make you into a shaliach mitzvah, one actively involved in a mitzvah (which offers protection from harm).”
The man was delighted; he didn’t even really expect a blessing, and now the Rebbe was giving him a mitzvah to perform on his behalf.
“Please send regards, in my name,” said the Rebbe, “to…. God in America.”
“But Rebbe,” the man said in embarrassed astonishment, “isn’t He the same God as the One here in Vienna?”
“Ah!” said the Rebbe, “if He’s the same God, then why are you going all the way to America for a livelihood? He could give it to you just as easily right here!”
With that message, the man decided to forgo his travel fare, and remain in Vienna with a newfound level of trust in Hashem.
Not only did the man’s finances begin to turn around for the better, but by staying in Vienna his life was saved, for the ticket that he had paid for was the Titanic boat (the ship termed at the time “The Unsinkable Ship”)which sank on its maiden voyage, drowning most of the passengers, including almost all of the male immigrants travelling from Europe to America.
 See Rashi 11:4 who tells us that the protagonists were in fact the eruv rav, the Egyptians who left Egypt with the Jewish People; however, the Jewish People nevertheless wept with them in a testament that they too were complaining about the situation.
 Rashi explains that the mannah would not taste of anything which was harmful for nursing mothers (Rashi 11:5).