Numbers 15:37-39

Again the LORD spoke to Moses, saying, “Speak to the children of Israel: Tell them to make tassels on the corners of their garments throughout their generations, and to put a blue thread in the tassels of the corners. And you shall have the tassel, that you may look upon it and remember all the commandments of the LORD and do them, and that you may not follow the harlotry to which your own heart and your own eyes are inclined