गुरुमूलमिदं सर्वं तस्मान्नित्यं गुरुं भजेत् ।
पुरश्चरणहीनोऽपि मन्त्री सिद्ध्येन्न संशयः ॥
guru-mūlam idaṁ sarvaṁ tasmān nityaṁ guruṁ bhajet |
puraścaraṇa-hīno’pi mantrī siddhyen na saṁśayaḥ ||
(Hari-bhakti-vilāsa: 17.242)
“The basis of all these [preliminary rites] is the guru. Therefore, always serve the guru. Thereby, even a mantra-sādhaka who has not performed any preliminary rites (puraścaraṇa) can attain perfection. Of this, there is no doubt.”