The Mantra is ॐ नमो नारायणाय (OM namo nArAyaNAya) and the quote under number 147 on the screenshot is from "Shree Narada-Purana".
Cited from
"Religion and Philosophy of Nalayira Divya Prabandham
with special reference to NammAlvar"
by Dr.N.Subbu Reddiar - #LINK TO PDF-SCAN
