成唯識論掌中樞要 2.196

2.196

「本識等」者第六識所變，以帶質通情本，今隨本說故。

As for 'the mūla-vijñāna and so forth,' they are what is manifested by the sixth consciousness; because they partake of an objective basis (帶質) that connects with both the subjective mind and the original entity, here they are spoken of in accordance with the original entity.