Look at what is surrendered. Oxen that plow, rams that breed the flock, lambs in the first year of their strength, the productive core of a man's wealth led away to the fire. Abidan does not offer the sick or the surplus. He gives creatures he had every reason to keep, because an offering that costs nothing purchases nothing. The future he wants is bought with the substance he already holds.
The ancient discovery underneath the ritual is that a person secures tomorrow by giving up something precious today. Store the whole herd and cling to it, and you have made an idol of the present. The animals on the altar are the present handed over on purpose, so that something better than the present can come. Sacrifice what you value now, deliberately, and you buy a future worth living in.