成唯識論述記 3.149

3.149

述曰：本識行相必杖境生，此唯所變，非心外法，本識必緣實法生故。若無相分，見分不生，即解本頌先境後行之所以也。杖謂杖託，此意總顯見託相生，大乘影像即是所變，緣有生心，非緣無也。有處說諸識必依緣有，本質方生，即以名教等為本質故，如下當辨，此略解訖。

The Commentary states: The ākāra of the fundamental consciousness must depend on an object to arise; this is solely what has been transformed, not a dharma outside of citta, because the fundamental consciousness must arise cognizing real dharmas. If there were no nimittabhāga, the darśanabhāga would not arise; this explains why the root verse places the object first and the cognitive activity afterward. 'Relying' means depending upon and leaning against; the general sense here shows that the darśana arises depending on the nimitta: in the Mahāyāna, the mental image (pratibimba) is precisely what is transformed, and consciousness arises by cognizing what exists, not by cognizing what does not exist. In some places it is said that all consciousnesses must arise by relying on and cognizing an existent basic substance (bimba), using names, teachings, and so forth as the basic substance; this will be analyzed below, and here it is briefly explained.