俱舍論記 24.139

24.139

「尊者妙音至故名法輪」者、釋後一句。尊者妙音作如是說：如世間輪有輻、轂、輞，八支聖道似彼名輪。正見等四依戒緣境，似世間輪輻。正語等三以戒為體，戒是眾行所依處故，似世輪轂。正定能攝正見等四令不散故，似世輪輞。故名法輪。

"The Venerable Ghoṣaka [...] therefore it is named the wheel of the Dharma" explains the latter line. The Venerable Ghoṣaka spoke thus: Just as a worldly wheel has spokes, a hub, and a rim, the eightfold noble path resembles it and is named a wheel. The four beginning with right view rely upon moral discipline to apprehend the objective realm, resembling the spokes of a worldly wheel. The three beginning with right speech take moral discipline as their entity, and because moral discipline is the basis of all practices, they resemble the hub of a worldly wheel. Right concentration can gather the four beginning with right view so that they do not disperse, resembling the rim of a worldly wheel. Therefore it is named the wheel of the Dharma.