Shiva Purana
प्रतिश्राद्धं ब्राह्मणानां युग्मं कृत्वोपकल्पितान् ॥ आहूय पादौ प्रक्षाल्य स्वयमाचम्य यत्नतः ॥ ४३॥
In every Śrāddha a pair of brahmins shall be invited and their feet washed. He shall then perform the Ācamana assiduously.
english translation
pratizrAddhaM brAhmaNAnAM yugmaM kRtvopakalpitAn ॥ AhUya pAdau prakSAlya svayamAcamya yatnataH ॥ 43॥
hk transliteration by Sanscript