俱舍論記 13.10

13.10

「謂心所思至謂思所作」者，答。思業謂心所思，思即是業，故名思業。思已業謂思所作，身、語二業思之所作，由思已作名思已業。

"It refers to mental volition... refers to what is done by volition" is the reply. Volitional karma (cetanā-karma) refers to the mind's volition; volition itself is karma, hence it is called volitional karma. Karma after having willed (cetayitvā-karma) refers to what is done by volition; the two karmas of body and speech are done by volition; because they are done after having willed, they are called karma after having willed.