Meditation is not an instrument of knowledge. It is a part of the way of deploying the instrument of knowledge, Upanishads. Patanjali Yoga does not say that meditation will give you liberation. Only knowledge can do that because the problem is ignorance,. And that ignorance can be removed by knowledge. What kind of knowledge? Knowledge of the distinction between consciousness and matter.
Swami Sarvapriyananda teaches the Chapter 6 (Verse 1) 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).