"You shall take of the first of every fruit of the ground that you bring in from your land that the Lord, your God gives you" Deuteronomy 26:2
Ma'aser, the tithe, was a far more substantial sacrifice than bikkurim, the first-fruits offering, amounting - as the Hebrew word indicates - to one-tenth of the farmer's income.
For the bikkurim, on the other hand no specific measure was fixed in Jewish law, yet it is the mitzvah of bikkurim that requires the ceremony of the carnival-like procession to Jerusalem and the ceremonious declaration of the farmer in the presence of the priest.
The farmer proclaims: "I declare today to God that I have come to the land that God swore to our fathers to give us… my father was a wandering Aramean and he went down to Egypt with a few people and lived there and became a great nation, numerous and powerful."
Why was it necessary for the person to praise himself by telling how, as it were, he had come "from rags to riches"? In none of the other mitzvot is a person required to tell others about it. On the contrary, it would be considered immodest to do so, and it would invalidate the mitzvah.
However, the underlying ethical message of the bikkurim is illustrated by the requirement that at the entrance to the Temple, the owner had to take a basket and carry it personally towards the Cohen. This obligation applied to everyone, no matter how rich or how poor, how lowly or how influential he was: even the king himself had to take his own basket to the priest. Indeed, the Tosephta tells of the king during the days of the Second Temple who carried the bikkurim on his own back, which earned him the admiration of the people.
The most important lesson, therefore, of the bikkurim is that it does not matter how much we give; what is important is the manner in which it is given.