法苑珠林 6.87

6.87

畜生者。如婆沙論中釋。生謂眾生。畜謂畜養。謂彼橫行。稟性愚癡。不能自立。為他畜養。故名畜生。問曰。若以畜養名畜生者。如諸龍水陸空行。豈可為人所養名為畜生耶。答曰。養者義寬。具滿人間及以六天。不養者處狹。唯在人中山野澤內。又古昔諸龍亦為人養。具在文史。今從畜養偏多。故名畜生。又立世論云。畜生梵名底（都履反）栗車。由因諂曲業故。於中受生故。復說。此道眾生多覆身行。故說名底栗車。

As for "animals" (chūsheng), as explained in the *Vibhāṣā-śāstra*, sheng means sentient beings, and chū means to raise or domesticate. It means that they walk horizontally, are by nature foolish and deluded, cannot sustain themselves, and are raised and domesticated by others; hence they are called "animals." The question is asked: If they are called animals because they are raised and domesticated, then how could dragons that move through water, on land, or through the sky be raised by humans so as to be called animals? The answer is: The meaning of "being raised" is broad, fully encompassing the human realm and up to the six [desire] heavens; while "not being raised" covers a narrow domain, existing only within the human realm, in mountains, wildernesses, and marshes. Furthermore, in ancient times dragons were also raised by humans, which is fully recorded in literature and history. Here, following what is predominantly domesticated, they are called animals. Moreover, the *Lokasthit[y-abhidharma]-śāstra* states: "The Sanskrit name for animal is tiryag-yoni (pronounced *dǐlìchē*). Because of karma of deceit and crookedness, they receive birth among them." It also says: "Sentient beings of this destiny mostly move with their bodies prone; therefore they are called tiryag-yoni."