Samadi is control of the mind. It is generated, held on and dissipates. The same in midst of work, bramhar parnam, brammahabi. That verse, it says, bramma karma samarina, the one who sees bramman in ail actions. You're actually doing work. T there is that one reality all the time in the midst of the active mind. This is knowledge.
Swami Sarvapriyananda teaches Chapter 6 (Verses 28-29) of the Bhagavad Gita. In this series of talks, Swami Sarvapriyananda unfolds the highest truths of Vedanta through the study of the Bhagavad Gita (The Song of God).