Verse 6

तामसैर्वासनाजालैर्व्याप्तं यज्जन्मकारणम् ।विद्यमानं मनो विद्धि तद्दुःखायैव केवलम्

In plain words

Know that the existent mind -- pervaded by webs of tāmasika vāsanās, and itself the very cause of birth -- is solely for sorrow.