As long as the spirit soul is covered by the subtle body, consisting of the mind, intelligence and false ego, he is bound to the results of his fruitive activities. Because of this covering, the spirit soul is connected with the material energy and must accordingly suffer material conditions and reversals, continually, life after life.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
यावल्लिङ्गान्वितो ह्यात्मा तावत्कर्म निबन्धनम् । ततो विपर्ययः क्लेशो मायायोगोऽनुवर्तते
yāvalliṅgānvito hyātmā tāvatkarma nibandhanam | tato viparyayaḥ kleśo māyāyogo'nuvartate
SB 7.2.47