Calvin's Commentaries, Vol. 3: Harmony of the Law, Part I, tr. by John King, [1847-50], at sacred-texts.com
37. And the Lord spake unto Moses, saying,
37. Dixit Jehova ad Mosen, dicendo:
38. Speak unto the children of Israel, and bid them that they make them fringes in the borders of their garments, throughout their generations, and that they put upon the fringe of the borders a ribband of blue:
38. Alloquere filios Israel, et dic eis ut faciant sibi fimbrias in angulis vestimentorum suorum, per generationes suas, et ponant in fimbria anguli filum hyacinthinum.
39. And it shall be unto you for a fringe, that ye may look upon it, and remember all the commandments of the Lord, and do them; and that ye seek not after your own heart, and your own eyes, after which ye use to go a whoring:
39. Et erit vobis instar fimbriarum, videbitisque eam, et recordabimini omnium praeceptorum Jehovae, ut faciatis ea: et non aspicietis post cor vestrum, et oculos vestros, post quos vos fornicamini.
40. That ye may remember, and do all my commandments, and be holy unto your God.
40. Ut recordemini, inquam, et faciatis omnia praecepta, et sitis sancti Deo vestro.
41. I am the Lord your God, which brought you out of the land of Egypt, to be your God: I am the Lord your God.
41. Ego Jehova Deus vester, qui eduxi vos e terra Aegypti, ut essem vobis in Deum: ego, inquam, Jehova Dens rester.
13. And in all things that I have said unto you be circumspect: and make no mention of the name of other gods, neither let it be heard out of thy mouth.
13. In omnibus quae praecepi vobis, cauti eritis.
38 Speak unto the children of Israel. A little farther on I will explain the object of this precept more fully: although it is plain from the next verse that God had no other object but to exercise the Jews in constant meditation upon the Law. For there was no religion contained in the fringes themselves, nor had that material texture any value in itself; but since men are lazy and forgetful in the cultivation of piety, God would by this aid make a provision for their infirmity. For when He says that they should “look upon it and remember,” He hints that they have need of these coarse rudiments, which may strike even their outward senses; and again, that, unless their memory was kept awake, nothing was more likely than that forgetfulness should steal upon them. But he presently adds, that God has no satisfaction in mere empty knowledge, but that He demands serious affections and practical performance. In the latter part of the verse he points out another requirement, viz., not only that their sluggishness should be stimulated, but also their wantonness restrained; for when he says “that ye seek not after your own heart,” he intimates that, unless God should restrain their wandering senses, they would be too much inclined to all kinds of superstitions and errors. And, first of all, by contrasting “the hearts and eyes” of men with His Law, he shews that He would have His people contented with that one rule which He prescribes, without the admixture of any of their own imaginations; and again, He denounces the vanity of whatever men invent for themselves, and however pleasing any human scheme may appear to them, He still repudiates and condemns it. And this is still more clearly expressed in the last word, when he says that men “go a whoring” whenever they are governed by their own counsels. This declaration is deserving of our especial observation, for whilst they have much self-satisfaction who worship God according to their own will, and whilst they account their zeal to be very good and very right, they do nothing else but pollute themselves by spiritual adultery. For what by the world is considered to be the holiest devotion, God with his own mouth pronounces to be fornication. By the word “eyes” he unquestionably means man’s power of discernment.
41 I am the Lord your God. Having at the end of the last verse commanded them to be holy unto their God, he now confirms this command by a reason, viz., that it was for this end that God redeemed them, that he might be their God, i.e., that He might be solemnly honored. He asserts God’s right, then, as founded upon the blessing of their deliverance, which would have been misplaced unless they devoted themselves to His service. The repetition at the conclusion is intended for confirmation.