Deuteronomy 6:5
4 Hear, O Israel: The Lord is our God, the Lord is one! 5 You must love the Lord your God with your whole mind, your whole being, and all your strength. 6 These words I am commanding you today must be kept in mind, 7 and you must teach them to your children and speak of them as you sit in your house, as you walk along the road, as you lie down, and as you get up.
Tobit 2:2
2 When the table was set for me and an abundance of food placed before me, I said to my son Tobias, "Go, my child, and bring whatever poor person you may find of our people among the exiles in Nineveh, who is wholeheartedly mindful of God, and he shall eat together with me. I will wait for you, until you come back." 3 So Tobias went to look for some poor person of our people. When he had returned he said, "Father!" And I replied, "Here I am, my child." Then he went on to say, "Look, father, one of our own people has been murdered and thrown into the market place, and now he lies there strangled."
Notes and References
"... There are five discernable echoes of Deuteronomy 6:5 in Tobit, words or phrases that refer to loving God or being mindful of God with all one’s heart, soul, or strength. What is most impressive is not so much each individual allusion to Deuteronomy 6, but the cumulative force of all five passages coupled with the literary and theological context of Deuteronomy 6 ... when Tobit sets out to invite a needy Israelite to his Pentecost banquet, he commands his son to search for someone “who is mindful of God with all his heart and bring him and he shall eat together with me” (Tobit 2:2) ..."
Baron, Lori Ann Robinson The Shema in John’s Gospel Against its Backgrounds in Second Temple Judaism (pp. 92-93) Duke University, 2015