Lord shiva is adi and he is only the anthya. He is the sole reason for the happenings in both the movable and immovable worlds. Therefore, it is said that not even a spring of grass will move without his permission. He is the one who has given life to all the creatures. He is also the one who takes away the lives of all the creatures. Sadhus sages and aghoraas practice severe penance without minding day and night on Lord Shiva.