Srimad Bhagavatam Canto 02, Chapter 10, Text 34

SB 2.10.34

atah param suksmatamam
avyaktam nirvisesanam
anadi-madhya-nidhanam
nityam van-manasah param
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Therefore beyond this [gross manifestation] is a transcendental manifestation finer than the finest form. It has no beginning, no intermediate stage and no end; therefore it is beyond the limits of expression or mental speculation and is distinct from the material conception.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
The gross external body of the Supreme is manifested at certain intervals, and thus the external feature or form of the Supreme Personality of Godhead is not the eternal form of the Lord, which has no beginning, no intermediate stage and no end. Anything which has a beginning, interim and end is called material. The material world is begun from the Lord, and thus the form of the Lord, before the beginning of the material world, is certainly transcendental to the finest, or the finer material conception. The ether in the material world is considered to be the finest. Finer than the ether is mind, intelligence and false ego. But all eight of the outward coverings are explained as outer coverings of the Absolute Truth. The Absolute Truth is therefore beyond the expression and speculation of the material conception. He is certainly transcendental to all material conceptions. This is called nirvisesanam. One should not, however, misunderstand nirvisesanam as being without any transcendental qualifications. Visesanam means qualities. Therefore nir added to it means that he has no material qualities or variegatedness. This nullifying expression is described in four transcendental qualifications, namely unmanifested, transcendental, eternal, and beyond the conception of mind or word. Beyond the limits of words means negation of the material conception. Unless one is transcendentally situated, it is not possible to know the transcendental form of the Lord.
Srimad Bhagavatam Canto 02, Chapter 10, Text 33
Srimad Bhagavatam Canto 02, Chapter 10, Text 35