Shiva Purana
भोजनान्ते रुद्रसूक्तं क्षमा पय्य द्विजान्मुनः ॥ तन्मन्त्रेण ततो दद्यादुत्तरापोशणं पुरः ॥ ६९॥
At the end of the meal he shall recite Rudra Sūkta. He shall ask forgiveness of the brahmins. After food he shall offer water.
english translation
bhojanAnte rudrasUktaM kSamA payya dvijAnmunaH ॥ tanmantreNa tato dadyAduttarApozaNaM puraH ॥ 69॥
hk transliteration by Sanscript