Shiva Purana
ॐमित्यन्ते जपन्देवयजनम्पूरयेत्ततः ॥ ततश्शान्तिर्भवेत्तस्य दोषस्य हि मुनीश्वर ॥ ४० ॥
Repeating Om in the end he shall complete the worship of the lord. O great sage, this procedure will quell the defect.
english translation
OMmityante japandevayajanampUrayettataH ॥ tatazzAntirbhavettasya doSasya hi munIzvara ॥ 40 ॥
hk transliteration by Sanscript