The word ‘pure’ in ‘pure consciousness’ traditionally denotes consciousness devoid of objects, ie. without the experience of objects. This is opposed to the ‘mixed’ or ‘reflected’ consciousness in which objects such as the mind, body and worldly objects appear.
Therefore to abide in pure consciousness means to turn away from objects, turn towards the Self/Subject and rest in Pure Being which is your True Nature.
This is why Shankara states in Vivekachudamani: ‘Dwelling on external objects will only increase evil propensities, so wisely recognising this fact, one should abandon external objects and and constantly attend to one’s true nature within, the Atman’.
For more information on how this is done please see here: