Discourse by Rev. Swami Bhajanananda Saraswati on mangalachana (auspicious invocation); achaman (sipping water); inner purification; pratahara (withdraw of sense and mind); Ganesh puja; Tantra; and the nature of symbolic images, language and actions; given at Kali Mandir Ramakrishna Ashram on 31 March 2018. This is part of a series of talks on the theory and practice of Kali Puja, the ritual worship of the Divine Mother Kali.