Tirukkural 411: Heaing Knowledge

Wealth (gained) by the ear is wealth of wealth; that wealth is the chief of all wealth.

Image of Satguru Sivaya Subramuniyaswami
Sadhana is performing the same discipline over and over and over again. Just as we methodically exercise the physical body to build up its muscles, we perform spiritual disciplines over and over again to strengthen our spiritual, inner bodies.
—Gurudeva