Tirukkural 767: The Excellence of an Army

That is an army which knowing the art of warding off an impending struggle, can bear against the dust-van (of a hostile force).

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