abhāvapratyayālambanā tamovṛttirnidrā

Deep sleep is when the mind is overcome with heaviness and no other activities are present.

Nidra means deep sleep, the dreamless state in which the mind is focussed on emptiness, void-ness.There are no thoughts arising in this state. The other activities of the mind (imagination, misconception, correct understanding, memory) do not come in to play. Nidra is an independent activity.

The sleep of a common man, where there are so many thoughts, dreams and nightmares are not addressed by Patañjali. I am not sure why. If any of you readers have a different interpretation or if you know where the common man’s sleep is addressed in the sutras, leave a comment.

abhāvapratyayālambanā tamovṛttirnidrā

abhāva -absence, non-existence, non-occurrence, negation, voidness, nothingness
pratyaya – the cause, the feeling, content of mind, presented idea, cognition
ālambanā – support, leaning on, dependent on, having as a base or foundation
tamo – heaviness
vṛtti – operations, activities, fluctuations
nidrā – deep sleep

Check out Vishnu’s peaceful sleep. His eyes are gently closed and looks like he is thoroughly enjoying his sleep. There are two demons on the right trying to create trouble, but Vishnu’s attendants on top are ready to stop the demons. Adi Sesa the snake, is at work providing Sthiram and Sukham. I love this sculpture.

This is part of the cave temples in Mamallapuram (Mahabalipuram). This cave temple has been scooped out of huge rock. These cave temples were built in 8th Century AD. I love temples or structures made of rocks, there is something about them that is instantly peaceful. And definitely, so much cooler inside compared to the outside temperatures of 40 degree Celsius.