למען ענותך ולמען נסותך להיטיבך באחריתך, "in order to afflict you and in order to test you, to do good for you in the end.⁠" All the tedium the people experienced during their trek in the desert was designed to subject them to a test to get them used to deal with such phenomena and to strengthen their faith when they would emerge from these tests each time. Faith in the Lord had to be instilled in them until it became their second nature (actually "first" nature). This is what David prayed for when he said in Psalms 25,5: "guide me in Your true way and teach me.⁠" The word למדני, "teach me,⁠" must be understood as similar to Jeremiah 2,24: פרא למוד במדבר, "a wild ass used to the desert" (trained in the desert). [The wild ass would not be wild if it had indeed been trained. The meaning is that it was unbridled and reflected the norms applicable in the desert. God used the Israelites' desert experience to train them to cope with adversity by relying on their God in heaven. Ed.]. Hoseah 10,11 using the example of a heifer, makes a similar point. David asked for God's assistance in training him to do His will until it would become his nature to do so, until it required little effort. We find the same wish expressed in Deut. 14,23 where the commandments of tithing and making pilgrimages to Jerusalem annually are used as prime examples of getting the Jewish people to "learn" to revere the Lord our God.
The reason why the Torah describes a people being fed manna from heaven as suffering, enduring an "affliction" in doing so is to teach that when someone does not have a food supply for a number of days ahead he is considered as enduring an "affliction.⁠" The fact that the supply of manna was only sufficient for one day at a time and the people had to depend on God's goodwill on a daily basis was an ענוי, a serious discomfort. Even the eating of such a limited food supply makes one conscious that there is nothing left when one has concluded one's meal, a fact which lessens' one's enjoyment. Psychologically, this is similar to the blind who cannot see what they eat and therefore do not enjoy it. Peace of mind, and therefore enjoyment of what one has in storage depends largely on one's ability to see and reassure oneself that one has no immediate worries. Scriptural proof for this is found in Kohelet 6,9 טוב מראה עינים מהלך נפש, "better what the eyes see than what the mind (only) imagines.⁠"