SB 9.8.22
ye deha-bhajas tri-guna-pradhana
gunan vipasyanty uta va tamas ca
yan-mayaya mohita-cetasas tvam
viduh sva-samstham na bahih-prakasah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
My Lord, You are fully situated in everyone’s heart, but the living entities, covered by the material body, cannot see You, for they are influenced by the external energy, conducted by the three modes of material nature. Their intelligence being covered by sattva-guna, rajo-guna and tamo-guna, they can see only the actions and reactions of these three modes of material nature. Because of the actions and reactions of the mode of ignorance, whether the living entities are awake or sleeping, they can see only the workings of material nature; they cannot see Your Lordship.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Unless one is situated in the transcendental loving service of the Lord, one is unable to understand the Supreme Personality of Godhead. The Lord is situated in everyone’s heart. However, because the conditioned souls are influenced by material nature, they can see only the actions and reactions of material nature, but not the Supreme Personality of Godhead. One therefore must purify himself internally and externally:
apavitrah pavitro va
sarvavastham gato ’pi va
yah smaret pundarikaksam
sa bahyabhyantarah sucih
To keep ourselves externally clean we should bathe three times daily, and for internal cleanliness we must cleanse the heart by chanting the Hare Krsna mantra. The members of the Krsna consciousness movement must always follow this principle (bahyabhyantarah sucih). Then it will one day be possible to see the Supreme Personality of Godhead face to face.