Compare Tobit 13:14 and Augustine, Confessions 4.9

“... The history of interpretation of the Book of Tobit has been a somewhat ne- glected area of scholarly investigation. Tobit’s canonicity was generally accepted in the Latin West (Jerome is a notable exception), but its status was debated in the Greek East, at least initially. It was excluded from the Jewish canon, possibly in part because the marriage of Tobias and Sarah did not conform to halakhic regulations. If indeed the reason for its canonicity among some Christians revolved around its high catechetical and pedagogical value, as suggested by Zenger, this would explain the fact that its primary function among early Christian preachers and exe- getes concerned spiritual formation and moral instruction. For example, Augustine alludes to the book of Tobit in his Confessions to describe the blessedness of loving God (4,9,14, citing Tob 13:14)6 and the importance of prayer (5,1,1, citing Tob 3:12). Likewise, in his work On Prayer, Origen takes the story of Tobit as having great teaching value for the way prayer should glorify God (14,4, citing Tob 3:1-2) and the efficacy of intercession (11,1 and 31,5, citing Tob 3:16-17 and 12:11-15).7 ...”