首楞嚴義疏注經 8.344

8.344

若望下文，此當六情四想也。橫生，旁生也。然有輕重，若情稍重，報為走獸，故曰毛群；若想稍強，身為飛禽，故云羽族。細論差別，如類生中及下文說。

Looking forward to the subsequent text, this corresponds to six parts emotion and four parts thought. 'Horizontal births' are animals. Yet there are lighter and heavier degrees: if emotion is slightly heavier, the retribution is to become a quadruped, hence called 'furred beasts'; if thought is slightly stronger, one's body becomes a flying bird, hence called 'feathered birds'. Detailed discussion of the differences is as explained in the classifications of birth and in the text below.