Skandapurana 2.4.30.150

2.4.30.150

taponiṣṭa tāpasasya ṭīkāyāṃ bindoḥṛṣeḥ ullekhamasti yaḥ paṃcanadatīrthe vratakaraṇasya parāmarśaṃ dadāti. upaniṣadeṣu oṃkārasya saṃdarbhe sārvatrikarūpeṇa bindu evaṃ nādasya ullekhāḥ santi. bindoḥ sthitiḥ arvāk asti, nādasya uttarā. anekānāṃ bindūnāṃ ullekhamasti, yathā mūlādhārasya binduḥ, cakṣuṣaḥ binduḥ, manasaḥ binduḥ. patisevā, pitṛsevādi kāryāṇi bindusthitiprāpaṇasya caraṇāḥ santi, ayaṃ pratīyate. yāvat pāpaḥ vidyamānaḥ asti, tāvat binduvat saṃghananaṃ saṃbhavaṃ nāsti. bindu avasthā prāptyuttaraṃ nādasya, nadasya prāptiḥ apekṣitā asti.

[Modern commentary:] In the commentary on the ascetic Taponiṣṭha, there is mention of the seer Bindu, who advises the observance of the vow at the sacred ford of Pañcanada. In the Upaniṣads, in the context of the Praṇava (oṃkāra), there are ubiquitous mentions of bindu and nāda. The state of bindu is earlier, while that of nāda is later. There is mention of numerous bindus, such as the bindu of the mūlādhāra, the bindu of the eye, and the bindu of the mind. It appears that actions such as service to the husband and service to the parents are steps toward attaining the state of bindu. As long as sin exists, concentration like a bindu is not possible. After attaining the state of bindu, the attainment of nāda, of the flow (nada), is required.