Shiva Purana
तत्रेशानादिसद्यांतं रुद्राद्यस्त्रांतमेव च ॥ शिवस्य वा शिवायाश्च प्रथमावरणे जपेत् ॥ ३ ॥
There are also weapons beginning with Lord Śiva and weapons beginning with Lord Śiva. One should chant the mantra of Shiva or Shiva in the first covering.
english translation
tatrezAnAdisadyAMtaM rudrAdyastrAMtameva ca ॥ zivasya vA zivAyAzca prathamAvaraNe japet ॥ 3 ॥
hk transliteration by Sanscript