“The citta is the one that naturally knows. It is only mere knowing – that is, knowing sensation, knowing conceptualising, knowing thinking, knowing hot, knowing cold, knowing seeing, knowing hearing or listening, and knowing smelling an odour or tasting a flavour – it makes genuine contact with all things of every kind. It doesn't know how to investigate or evaluate; it can't decide anything at all. Thus it is something which we say doesn't know good, doesn't know evil, doesn't know wrong, doesn't know right.
Sati (mindfulness) is what oversees. It has power over the citta. It is able to know the citta in real-time, and it can know the affairs of the citta well: "now the citta is in a good state", or "now the citta is not in a good state" – all of the time until it is truly able to look after and manage the affairs of our citta to make them good.
Practitioners in this dispensation of the Buddha thus determine to set up the substance of mindfulness, which has power over the citta, establishing it before them to do the applied work of knowing the citta...”
– Luang Pu Singh Khantayāgamo