37 The Lord spoke to Moses: 38 “Speak to the Israelites and tell them to make tassels for themselves on the corners of their garments throughout their generations, and put a blue thread on the tassel of the corners. 39 You must have this tassel so that you may look at it and remember all the commandments of the Lord and obey them and so that you do not follow after your own heart and your own eyes that lead you to unfaithfulness. 40 Thus you will remember and obey all my commandments and be holy to your God. 41 I am the Lord your God, who brought you out of the land of Egypt to be your God. I am the Lord your God.”
7 Light is sweet, and it is pleasant for a person to see the sun. 8 So, if a man lives many years, let him rejoice in them all, but let him remember that the days of darkness will be many—all that is about to come is obscure. 9 Rejoice, young man, while you are young, and let your heart cheer you in the days of your youth. Follow the impulses of your heart and the desires of your eyes, but know that God will judge your motives and actions. 10 Banish emotional stress from your mind and put away pain from your body; for youth and the prime of life are fleeting.
Notes and References
"... When scholars note what Thomas Krüger (2004, 196) calls the “provocative allusion” to Numbers 15:39 in Ecclesiastes 11:9, they rarely comment on the nature of the allusion beyond observing, like the rabbis, the way it “blatantly contradicts” Numbers. The rabbis’ concern does seem to be with a potential contradiction in meaning and not necessarily Qoheleth’s direct allusion to and rejection of the Numbers text. One midrashic reading even justifies the necessity of the apparently self-evident command in Numbers 15:39 to choose “the right way” over “any way [one] likes” by arguing that it serves as a corrective to Ecclesiastes 11:9. The lexical connections between the two verses are indeed rather limited. “Heart” and “eyes” are common terms. However, even though the allusion is subtle, when combined with the strong thematic link, it is certainly recognizable, as its recognition by the rabbis and numerous scholars demonstrates. It appears the author of Ecclesiastes had Numbers 15:39 in mind when he wrote and that he wanted his readers to recall the verse as well ..."
Kynes, Will "Follow Your Heart And Do Not Say It Was A Mistake: Qoheleth's Allusions To Numbers 15 And The Story Of The Spies" in Dell, Katharine Julia, and Will Kynes (eds.) Reading Ecclesiastes Intertextually (pp. 15-27) Bloomsbury T&T Clark, 2014