Sutra I. 37 Vita-raga-visayam va cittam

Commentary: Especially in the beginning of our spiritual practice when the pathways call to be opened up -- when the mind still is heavily addicted and afflicted with kleshas and vrtti, it is very helpful to not only to associate with spiritual friends who are on the path who reflect, reinforce, and remind us of light, love, clarity, and grace, but also to avoid people and situations who being dominated by similar kleshas (ignorance, fears, jealousies, hatred, anger, desire, greed, and the like) to our own might reinforce our negative tendencies and illusions.

Before each and every practice if not throughout the day, the yogis of the three times (those who are thus gone) who have passed through the veil -- the beings of eternal light are available for help if we ask for their aid and invite them in (invoke them). Also living is a spiritual community helps. One may also reflect on isvara, the param purusa, the ishta deva, the clear self luminous light free from all attachment (emptiness) which the essence of one's own true nature. Such practices as well as Arati and guru yoga invoke the eternal teacher of even the most ancient teachers (isvara) into our lives. this is darshana -- partaking of the light of the light and incorporating it into oneself by self acknowledgement.

For example in guru yoga, one invokes the timeless and formless intrinsic all pervading wisdom which the guru (as the remover or darkness) invokes. Thus the guru simply acts as transmitter, vehicle, or mirror for that which is entirely pure, timeless, universal, and unbiased. Thus we can invoke that same imperishable light which is latent inside, which is available to us always at any time, whether or not we receive darshan from an enlightened teacher (keeper of the light which removes darkness) in physical proximity, whether we use images, pictures, mantras, mystical diagrams, or communion with the formless self effulgence directly.

This can also be taken as advice for new practitioners to cultivate the company of the wise who will acknowledge and reflect back to you the truth of who you truly are and what truly is; while avoiding needless contact with those who are jealous, greedy, prideful, confused, and who will reinforce and project on to you your false identifications, limitations, and conditioned "self".

also see I.19, III.43, III.46.