The milk is the Knowledge and Power descending from the Divine Consciousness. Milk is always the symbol of the flow of the higher consciousness.
The ease and peace are felt very deep and far within because they are in the psychic and the psychic is very deep within us, covered over by the mind and vital. When you meditate you open to the psychic, become aware of your psychic consciousness deep within and feel these things. In order that these ease and peace and happiness may become strong and stable and felt in all the being and in the body, you have to go still deeper within and bring out the full force of the psychic into the physical. This can most easily be done by regular concentration and meditation with the aspiration for this true consciousness. It can be done by work also, by dedication, by doing the work for the Divine only without thought of self and keeping the idea of consecration to the Mother always in the heart. But this is not easy to do perfectly.
If one can remain always in the higher consciousness, so much the better. But why does not one remain always there? Because the lower is still part of the nature and it pulls you down towards itself. If on the other hand the lower is transformed, it becomes of one kind with the higher and there is nothing lower to pull downward.