Each letter in a sefer Torah teaches us countless lessons. The letter alef of the word "Vayikra" teaches us the significance of humility. According to tradition, this letter is written smaller than other letters in a sefer Torah. Chazal explain that this is because Moshe was humble and would have preferred that the word have been "vayikar" rather than "Vayikra". What is the difference of meaning between these two words, and how does this distinction symbolize the trait of humility that characterized Moshe?
In contrast to Moshe, there was another navi who the word vayikar is used to describe Hashem speaking to him; Vayikar is how Hashem addresses Bilam. The word vayikar is related to the word mikra - an event that "happens" to take place. Hashem does not speak to Bilam with regularity. Rather, whenever the need arises Bilam receives a prophecy. In contrast, Moshe is spoken to by Hashem all the time. Moshe even initiates conversation with Hashem several times when he needs guidance from Hashem about a particular halacha such as Pesach Sheini and the claim of benos Tzlafchad.
Although Moshe and Bilam were both nevi'im, they related to their nevuah in radically different ways. Bilam constantly boasts of his role as a navi. He describes himself in glorious terms as one who hears the word of Hashem and who has knowledge of the Divine. He only eventually admits to Balak that "Oo'ly yikrah Hashem likrosi - maybe Hashem will appear to me." Balak is elated when called upon to prophesize and he uses this gift to amass great personal wealth. In contrast, from the first time Hashem speaks to Moshe at the sneh he shies away from the nevu'ah. He sees himself as a kvad peh - one who has difficulty speaking and not worthy of being a navi. Even when finally accepting his role as a navi, Moshe would rather be referred to as vayikar - as one who is on a lower level of nevuah not meriting the constant word of Hashem.
It is precisely this difference between Moshe and Bilam that resulted in the very different culminations of their roles as nevi'im. Bilam, who constantly sought glory for his gift of nevu'ah, is ultimately humiliated; the nevu'ah that is granted to him blessing the Jewish People are the final words he speaks in the name of Hashem. Moshe, on the other hand, who was the humblest man ever to live, became the greatest of all nevi'im and merited the highest level of nevu'ah, i.e. conversing with Hashem "peh el peh". Bilam, who prided himself on his ability to see, eventually saw less than his donkey. Moshe became the one to see b'aspaklaria ha'me'irah, i.e. the clearest vision given to man.
The reason this fundamental lesson of humility is taught to us specifically at the beginning of sefer Vayikra which focuses on korbanos is that the offering of a korban is an expression of humility, since many korbanos are brought as a kapara for a cheit. The teshuva process which culminates with the offering of a korban is predicated on the ability to humble oneself before Hashem, in contrast to the arrogant individual who cannot admit he made a mistake. The korbanos that are brought as an expression of thanks also require a sense of humility. How so? One who views his success as a result of his own accomplishments will not acknowledge that it is Hashem who really has bestowed upon him these gifts; he will feel no need to offer thanks. A korban of thanks to Hashem, by contrast, is the ultimate expression of the realization that we are humbled by the goodness He performs for us.
Bilam, who was the antithesis of humility, also offers korbanos. Throughout Parshas Balak he draws attention to these korbanos and prides himself on bringing them. He uses them as a way to demand that Hashem grant him nevu'ah. Rather than internalizing the lesson of humility signified by korbanos, he uses them to advance his arrogance as he attempts to further his personal status and wealth.
As we begin Sefer Vayikra, the very first word teaches us about the proper spirit that must accompany a korban. We look to Moshe as a role model of humility to guide us in how to use korbanos as a vehicle for teshuva and as an acknowledgement of our complete dependence on Hashem for the gifts He bestows upon us.