諸經要集 17.84

17.84

又四品學經云。凡俗之人或有不如畜生。畜生或勝於人。所以者何。人作罪不止。死入地獄。罪畢始為餓鬼。餓鬼罪畢轉為畜生。畜生罪畢乃還為人。以畜生中畢罪。便得為人。是故當勤作善。奉三尊之教。長離三惡道受天人福。後長解脫。

The Sipin xue jing also says: Common mortals may sometimes be inferior to animals, and animals may sometimes surpass humans. Why is this? A person commits sins without stopping and at death enters hell. When the retribution for sin is finished, he first becomes a hungry ghost. When the sin of the hungry ghost is finished, he turns into an animal. When the sin of the animal is finished, only then does he return to being a human. Because he finishes his sins among the animals, he then attains human form. Therefore, one should diligently practice good deeds and follow the teachings of the Three Honored Ones, leaving the three evil destinies forever behind to receive the bliss of gods and humans, and ultimately attain permanent liberation.