Nārada Muni continued: After trying this process for many, many births and remaining unattached to material contamination, placing themselves continually in trance and executing many types of austerities, many mystic yogīs were unable to find the end of the path of God realization.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
मुनयः पदवीं यस्य निःसङ्गेनोरुजन्मभिः । न विदुर्मृगयन्तोऽपि तीव्रयोगसमाधिना
munayaḥ padavīṃ yasya niḥsaṅgenorujanmabhiḥ | na vidurmṛgayanto'pi tīvrayogasamādhinā
SB 4.8.31