The Rav of Tcherin wrote in Zimrat Ha'aretz...

The perfection of hitbodedut (secluded meditation) is to attain devekut (cleaving to or communion with G-d), to cleave to G-d until you become utterly subsumed with the Divine Oneness.

The word hitbodedut is a construct of badad, meaning either 'seculsion' or 'oneness', as in the phrase 'they shall be one with one [ie, of equal weight]' - Rashi on Exodus 30:34. That is, you must become "one with G-d" to the extend that all sensory awareness ceases and the only reality you perceive is Godliness. This is the mystical meaning of the verse "There is nothing but G-d alone" - Deuteronomy 4:35.

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