1) Ch. 15, v. 2: "Zeh Keili v'anveihu" This is my G-d and I will glorify Him The gemara Shabbos 133b derives from these words that one should not do mitzvos "on the cheap," but rather, should beautify them. The halacha is that one should upgrade the quality of a mitzvoh up to a third more than the basic/available cost. Why is this concept placed in these words?
2) Ch. 15, v. 22: "Va'yeilchu shloshes yomim bamidbor v'lo motzu moyim" And they traveled for three days in the desert and did not locate water How did they survive for three days without water?
3) Ch. 16, v. 25: "Ki Shabbos ha'yom" Because it is Shabbos today Rashi explains that they received no manna Shabbos morning and came back again in the evening, asking if they should look for manna. This is most puzzling. They never received manna at night, so why should they inquire about evening manna?
4) Ch. 16, v. 35: "Arbo'im shonoh" Forty years Ibn Ezra writes that among all of the miracles Moshe wrought, this is the greatest. This is because it was not a short-lived miracle, but a continuous one that lasted forty years. Ibn Ezra, in his final comment on parshas Mishpotim writes that Moshe's remaining alive even though he did not eat nor drink for forty days and nights is the greatest wonder heretofore. We must differentiate between the term "nes," used here, and "pelle," used there.
Why was the miracle of the wellspring of Miriam not of equal stature? True that it came in the merit of Miriam, but Moshe wrought it. As well, the wellspring gave water even on Shabbos and Yom Tov, while the manna did not descend on Shabbos, nor on Yom Tov.
5) Ch. 16, v. 35: "Ad bo'om el eretz nosho'ves es hamon ochlu ad bo'om el k'tzei eretz K'no'an" Until their coming to an inhabited land the manna they eat until they came to the edge of the land Canaan Rashi explains that the earlier part of the verse means that they still ate manna that remained in their vessels until the 16th of Nison, and the latter part refers to the actual falling of manna, which lasted only as long as Moshe was alive (see gemara Kidushin 38a). This seems to be a contradiction to his words in the previous verse, where he says that the manna ceased on the 15th of Nison.