SB 5.11.16
na yavad etan mana atma-lingam
samsara-tapavapanam janasya
yac choka-mohamaya-raga-lobha-
vairanubandham mamatam vidhatte
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The soul’s designation, the mind, is the cause of all tribulations in the material world. As long as this fact is unknown to the conditioned living entity, he has to accept the miserable condition of the material body and wander within this universe in different positions. Because the mind is affected by disease, lamentation, illusion, attachment, greed and enmity, it creates bondage and a false sense of intimacy within this material world.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The mind is the cause of both material bondage and liberation. The impure mind thinks, “I am this body.” The pure mind knows that he is not the material body; therefore the mind is considered to be the root of all material designations. Until the living entity is aloof from the association and contaminations of this material world, the mind will be absorbed in such material things as birth, death, disease, illusion, attachment, greed and enmity. In this way the living entity is conditioned, and he suffers material miseries.