We find ourselves at present in the midst of the days between Passover and Shavuot. Some refer to these days as "the Days of the Counting of the Omer," a title which brings to mind the "Intermediate Days" (Yemei Chol HaMo'ed): they begin with Passover, the first day of the "Festival," and end with Shavuot. The intermediate days are bound by the act of counting. We bind the Festival of Freedom, which commemorates our Exodus from the Egyptian house of bondage, with Shavuot, which celebrates our spiritual freedom, the receiving of the Torah.

This teaches us that this entire process is a single and complete unit. There is no meaning to physical freedom if it does not lead us to a spiritual goal, in the sense of "if there is no Torah - there is no flour" (Mishna Avot 3:17). There is no point or meaning to flour, i.e., physical existence, if we do not arrive at the spiritual goal - Torah. At the same time, the perfection of spiritual freedom depends upon physical freedom, in the sense of "if there is no flour, there is no Torah" (ibid.). This, then, is the meaning of the bond, the attachment of these two days through the counting of the Omer. The first advances and proceeds in the direction of the second, while, at the same time, the second is attached to, and based upon, the starting point of the first.

Let us take a look at the commandment of the Omer offering, its content and meaning. The Sages tell us that the Omer offering must be waved, for the chapter in the Torah dealing with the Omer repeats the word "wave" a number of times and in varying manners:

"And he shall wave the sheaf before the Lord, to be accepted for you; on the next day after the sabbath the priest shall wave it" (Leviticus 23:11).
And you shall offer that day when you wave the sheaf..." (ibid. 12)
"...from the day that you brought the sheaf of the wave offering..." (ibid. 15)
And on the fiftieth day, after the counting of the seven weeks, we bring " wave loaves" (ibid. 17), "And the priest shall wave them with the bread of the first fruits for a wave offering before the Lord" (ibid. 20).
In this chapter dealing with the counting of seven weeks, waving is mentioned seven times!
How is the waving carried out?
"He moved it forward and backward, upward and downward; forward and backward to symbolize that the act was in honor of Him to whom the whole world belongs; upward and downward to symbolize that the act was in honor of Him to whom belong the regions on high and the regions below" (Pesikta DeRav Kahana, HaOmer).

In other words, moving our arms in all directions is meant to stir us to consider all which surrounds us, to know that the entire world belongs to the Almighty, the entire array of the cosmos is operated by Him. We must know and make others aware of the fact that the entire universe belongs to Him, He created it and He continues to operate it. And we, by thanking Him, publicize to all that the blessing comes from Him, "For all things come from You, and of Your own have we given You" (Chronicles 1 29:14).

This is the declaration and announcement of the waving of the Omer, forward, backward, up and down. It serves as recognition that all of the workings of nature are to be attributed to the Almighty. The Sages of the Midrash thus portrayed things (Pesikta DeRav Kahana):
"R' Yannai observed: In the ordinary way, if a man buys a pound of meat in the market, how much trouble he must go through, how much anxiety he must suffer until he cooks it! Yet though people are asleep upon their beds and the Holy One, blessed be He, causes winds to blow, clouds to rise, plants to grow, and fruits to be plump, they only give Him the reward of a sheaf; as is implied by the text, 'Ye shall bring the sheaf of the first-fruits of your harvest unto the priest.'"

When we bring the first-fruits of our harvest, we are thankful to God, for we would not be able to enjoy the blessing of our labor alone; we are dependent upon God's kindness which aids us via the intricate workings of the laws of nature. And this explains the prohibition against harvesting and eating the new grain ("chadash") until after the offering of the Omer sacrifice. How can we enjoy this new produce before recognizing and thanking the Creator, for, after all, He is the source of this blessing, the germinal force causing its actualization.

----
Translated sources in the above article are taken from or based upon the Soncino Classics Library, CD-Rom edition.