Skandapurana 6.3.161.8

6.3.161.8

mārgaśīrṣasya māsasya kṛṣṇapakṣe ca yāṣṭamī .
sopavāsaḥ śucirbhūtvā liṅgaṃ sampūrayettilaiḥ .
yathāvibhavasāreṇa gandhapuṣpaiḥ samarcayet .. 161.8 ..

On the eighth day in the dark fortnight of the month of Mārgaśīrṣa, / having fasted and become pure, one should cover the liṅga with sesame seeds / and worship it with fragrant pastes and flowers according to one's wealth.