Truth is the essence of the Vedas. The essence of Truth is self-control. The essence of self-control is Liberation. This is the teaching of all the scriptures.
वेदस्योपनिषत् सत्यं सत्यस्योपनिषद् दमः। दमस्योपनिषन्मोक्ष एतत् सर्वानुशासनम्॥