瑜伽論記 7.155

7.155

於聞思中，力勵運轉、有間運轉者，謂從聞思加行，已得所修未至定中作意，從此已後世出世道可漸勝進，能得所修三摩地作意，了相在初，猶為欲界思慧間雜色相出入，不能一向純定心轉，故名有間。泰師等云：作意名憶，然與定作名說定名作意也。

Regarding "forcefully operating and intermittently operating within hearing and thinking": it means that from the preparation of hearing and thinking, one has already obtained the mental engagement within the access concentration to be cultivated; from this point onward, mundane and supramundane paths can gradually advance with excellence, enabling one to attain the cultivated mental engagement of samādhi. The comprehension of marks (lakṣaṇapratisaṃvedī) is at the beginning, yet it is still interspersed with the wisdom resulting from thinking (cintāmayī prajñā) belonging to the desire realm and with images of matter entering and departing, unable to operate purely with an exclusively concentrated mind; thus it is called "intermittent." Master Tai and others say: mental engagement is called recollection, but by being named together with concentration, concentration is called mental engagement.