Intellectual Excellence in Purity

Gemara:
[In the declaration upon fulfilling the mitzvot of ma’aser, one says] "…I did not consume it in a state of impurity" – for if he separated [the ma’aser sheni] in impurity, he is not able to make the declaration.

Ein Ayah: [In the previous piece, Rav Kook explained how ma’aser sheni represents the intellectual side of a person, which is comparable to kehuna. Just as there are people who are kohanim, involved in sanctity within the nation, so too each person has a "kehuna-like" side within him. Ma’aser sheni is a food that a non-kohen eats in sanctity to remind him that he indeed has this element within him.]
The recognition that man has a special status – he contains within him an element of kehuna in which his intellectual side is found – is something that should be important to him. However, he still needs to be very careful to avoid exaggeration, which is common. This exaggeration can blind a person and make him fall into the trap of haughtiness, in which he views himself as a flawless person with no negative traits to correct.
This can occur when one loves himself more than he should, which happens when improper inclinations intermingle with the good inclinations that are within him. Therefore, one has to be more careful when he is involved in considering his own intellectual side than when he is involved in an activity that causes him to contemplate the special value that his counterpart possesses. The activity that reminds one of his own special value is the taking off of ma’aser sheni, and the activity that reminds him of the special value of another person is the giving of teruma to a kohen. That is why one who is setting aside ma’aser sheni must be very careful to not take off ma’aser sheni within a context of impurity.
On the other hand, he should not give up on the recognition of his level but should find a time and a place in which he will be able to consume the ma’aser before Hashem. From the perspective of his intellectual side, he should realize that he is on the level to eat from the "table of divinely-connected food." This requires him to be on a path of purity, a humility of justice, and a clean mind. That is why, in regard to the setting aside of ma’aser sheni, the Torah writes that if there was impurity involved in taking off the ma’aser sheni, he is not able to make the relevant declaration.