ייִדישער מחשבֿה אויף תהילים 96:12

Unless there is gratitude for favours received, what would keep the world going? G-d created the universe as an act of kindness, and even though it is not within our capacity to return this kindness even minimally, especially since G-d is not in need of anything, ingratitude on our part would negate the act of generosity by G-d. "heavenly beings accord Him honour, gratitude." (Psalms 29,2) Human beings are similarly asked to do so, each according to their status and stature in the universe. The letters at the beginning of the verse in the nishmat Sabbath morning prayer which spell Yitzchak and Rivkah respectively, suggest that just as that pair of human beings was perfectly matched, so our praise of G-d has to match the nature of the gifts He has bestowed upon us. This rule applies even for beings not possessed of life as we know it. "All the trees of the forest will break out in jubilation" (Psalms 96, 12.) The world is arranged in such a way that all higher forms of creatures contribute to, and endow the lower forms of life, with some of their superior attributes and capabilities. The exchange of ideas, possessions, etc. is of course, most evident in the economic life of man. Since economic self sufficiency does not exist within any single individual, the species would face annihilation were it not for such mutual bestowing of benefits upon one another, albeit for mundane purposes. Therefore, ingratitude is the basest of all bad character traits. The Talmud in Taanit 8, states "rain descends on account of those who keep faith; it is withheld because of those who act wilfully and brazenly." All the favours received from G-d, fall under one of three headings. 1) Life; 2) wisdom, knowledge; 3) livelihood, sustenance, (compare chapter forty two in Isaiah, chapter two in Proverbs and chapter 145 in the book of Psalms) Our prayers reflect our gratitude for these three kinds of loving kindness shown us by G-d. A) "Elokai neshamah..." thanks to G-d for waking up alive each morning. B) "Asher natan lasechvee beenah,” who has endowed even the rooster with wisdom." C) "Malbish arumim, zokef kefufim," who provides clothing for the naked, helps those bent over to resume erect posture etc. This is the reason that we recite Psalm 100, a hymn of thanksgiving. Since it is obviously impossible for man to express his gratitude adequately, G-d commands us to give three times a half a shekel. In this way, we express symbolically that we owe gratitude for the three aspects of kindness received from G-d on an ongoing basis. This is what is meant by the expression kofer nefesh. We thank G-d for the gift of meaningful life, for the knowledge and reason granted, enabling us to lay the foundation of the tabernacle which represents the seat of Torah wisdom. Finally, we thank G-d for the legislation of sacrifices, by means of which we express our acknowledgment that He is the source of our food and sustenance.