The words bhaktyā kevalayā indicate that simply by executing devotional service one can become full of all knowledge. Kṛṣṇa is the master of all knowledge ( aiśvaryasya samagrasya vīryasya yaśasaḥ śriyaḥ ). The Lord is situated in everyone’s heart ( īśvaraḥ sarva-bhūtānāṁ hṛd-deśe ’rjuna tiṣṭhati ), and when the Lord is pleased with a devotee, the Lord instructs him. Only to the devotees, however, does the Lord give instructions by which to advance further and further in devotional service. To others, the nondevotees, the Lord gives instructions according to the manner of their surrender. The pure devotee is described by the words bhaktyā kevalayā. Śrīla Viśvanātha Cakravartī Ṭhākura explains that bhaktyā kevalayā means jṣāna-karmādy-amiśrayā, “unmixed with fruitive activities or speculative knowledge.” Simply surrendering at the lotus feet is the cause of all a devotee’s enlightenment and awareness.