Shiva Purana
अग्निरित्यादिभिर्मंत्रैर्भस्म संधारयेत्ततः ॥ शिरसि श्रीगुरुं नत्वा मण्डलं रचयेत्पुनः ॥ ४॥
Then one should hold the ashes with mantras like Agni. Bowing to Sri Guru on the head, one should again form a circle.
english translation
agnirityAdibhirmaMtrairbhasma saMdhArayettataH ॥ zirasi zrIguruM natvA maNDalaM racayetpunaH ॥ 4॥
hk transliteration by Sanscript