Genesis 4:15
13 Then Cain said to the Lord, “My punishment is too great to endure! 14 Look, you are driving me off the land today, and I must hide from your presence. I will be a homeless wanderer on the earth; whoever finds me will kill me!” 15 But the Lord said to him, “All right then, if anyone kills Cain, Cain will be avenged seven times as much.” Then the Lord put a special mark on Cain so that no one who found him would strike him down. 16 So Cain went out from the presence of the Lord and lived in the land of Nod, east of Eden. 17 Cain was intimate with his wife, and she became pregnant and gave birth to Enoch. Cain was building a city, and he named the city after his son Enoch.
Leviticus 26:18
16 I for my part will do this to you: I will inflict horror on you, consumption and fever, which diminish eyesight and drain away the vitality of life. You will sow your seed in vain because your enemies will eat it. 17 I will set my face against you. You will be struck down before your enemies; those who hate you will rule over you, and you will flee when there is no one pursuing you. 18 “‘If, in spite of all these things, you do not obey me, I will discipline you seven times more on account of your sins. 19 I will break your strong pride and make your sky like iron and your land like bronze. 20 Your strength will be used up in vain; your land will not give its yield, and the trees of the land will not produce their fruit.
Notes and References
"... the way one treats the poor is understood to have a direct bearing on how one can expect to be treated by God. The correlation is so strong here in the Syriac addition that the author does not promise a future recompense in kind, but instead uses the participial form giving the sense “you are covering.” This rhetorical move essentially side-steps the possibility that the model would break down by telescoping the deed and its consequence. It is understood to be automatic. The rationale is developed further in verses 28g-h. The conjunctive at the beginning of verse 28 indicates that these two stichs flesh out the theological dynamic in verse 28. As indicated above, stichs g-h represent an elaboration of the idea in Proverbs 19:17 in light of Sirach 35:13. However, whereas Proverbs 19:17 states only that God will repay, in 35:13 and 29:28 it said to be “sevenfold.” In the Hebrew Bible the idea of “sevenfold” occurs only in retributive contexts to describe punishment (e.g. Genesis 4:15-24; Leviticus 26:18-28; Psalm 79:12; Proverbs 6:31) ..."
Gregory, Bradley C. Like an Everlasting Signet Ring: Generosity in the Book of Sirach (p. 216) De Gruyter, 2010