Shiva Purana
शुचिर्बद्धशिखस्सूत्री सपवित्रकरस्तथा ॥ धृतत्रिपुंड्ररुद्राक्षो विद्यां पञ्चाक्षरीं जपेत् ॥ २७ ॥
He shall perform the Japa of the five-syllabled mantra, pure in person and mind, with the tuft tied up, wearing the sacred thread on the body and having the Pavitra round the finger. He shall have the Tripuṇḍra marks and shall wear Rudrākṣa beads.
english translation
zucirbaddhazikhassUtrI sapavitrakarastathA ॥ dhRtatripuMDrarudrAkSo vidyAM paJcAkSarIM japet ॥ 27 ॥
hk transliteration by Sanscript