俱舍論頌疏論本 4.63

4.63

釋曰：心意識體一者，集起名心，謂能集起三業事也。思量名意。了別名識。復有釋言：淨不淨界種種差別，故名為心（淨者善也，不淨者惡也，界者體也）。即此為他作所依止，故名為意。即此者，即此心也。將所依義，釋意也。作能依止，故名為識，識能依意也。據上兩解，是心、意、識三名義雖異，其體一也。

The commentary explains: Regarding "Citta, manas, and vijñāna are one in substance": accumulating and giving rise is called citta (mind), meaning capable of accumulating and giving rise to the matters of the three karmas. Cogitating is called manas (intellect). Discerning is called vijñāna (consciousness). There is another explanation: because of the various distinctions of pure and impure realms, it is called citta (pure means wholesome, impure means unwholesome, realm means substance). Because this very thing acts as a basis for others, it is called manas; "this very thing" means this very citta; the meaning of "basis" is used to explain manas. Because it acts as that which relies on the basis, it is called vijñāna, for consciousness is capable of relying on the intellect. According to the above two explanations, although these three names—citta, manas, and vijñāna—differ in meaning, their substance is one.