(9) It shall be for a sign unto thee upon thine hand, and for a memorial between thine eyes.--The practice of wearing tephillin, or "phylacteries," is referred by the Jews themselves to the time of the Exodus, and regarded by them as resting on the present passage, together with Deuteronomy 6:8; Deuteronomy 11:18. These phylacteries consist of small strips of parchment, on which are written certain passages from the Law--viz., Exodus 13:2-10; Deuteronomy 6:4-9, and Deuteronomy 11:13-21--and which are then folded tight, placed in small boxes, and attached by bands to the left wrist and the forehead at the hours of prayer. It is well known that a similar custom prevailed in Egypt (Wilkinson, Ancient Egyptians, Deuteronomy 11:18). [Dean Plumptre notices, in his Commentary on the Temptation (St. Matt.), that our Blessed Lord used against the adversary quotations from the Scriptures forming these very Tephillin.]

Verse 9. - And it shall be for a sign unto thee upon thy hand, and for a memorial between thine eyes. There can be no doubt that the Jewish system of tephillin, or "phylacteries," grew mainly out of this passage, and was intended as a fulfilment of the commands contained in it. The tephillin were strips of parchment with passages of Scripture written upon them and deposited in small boxes, which were fastened by a strap either to the left arm, or across the forehead. The modern Jews argue that they were what Moses here intended, and that their employment began from this time. Some Christian commentators agree with them. But the great majority argue, from supposed probability and from the entire absence of any reference to the actual wearing of tephillin in the Old Testament, that the custom must be, comparatively speaking, a modern one. It is generally supposed to have originated, with other superstitious practices, in the time of the Babylonish captivity. Those who take this view regard the words of Moses in the present passage as merely metaphorical, and compare them with Proverbs 3:3; Proverbs 6:21; Proverbs 7:3. Kalisch, however, observes with reason, that if the injunction to write passages of the Law on the door-posts of their houses (Deuteronomy 6:9; Deuteronomy 11:20) was intended to be understood literally, and was literally carried out (Isaiah 57:8), the commands with respect to tephillin, which are coupled with them (Deuteronomy 6:8; Deuteronomy 11:18) must have been similarly intended. And probability, which is said to be against the Mosaic origin of tephillin, may perhaps rather be urged in its favour. The Egyptian practice Of wearing as amulets "forms of words written on folds of papyrus tightly rolled up and sewn in linen" (Wilkinson's Ancient Egyptians, vol. 3. p. 364) is well attested. Would it not be in harmony with the general character of his legislation, that Moses should adopt and regulate the custom, employing it to do honour to the Law and keep it in remembrance, without perhaps purging it wholly from superstitious ideas? Moses allowed the Israelites in many things "for the hardness of their hearts," content if he could introduce some improvement without insisting at once on an impracticable perfection. That the law of the Lord may be in thy month. The Israelites are instructed from the first, that the tephillin are to be a means to an end; and that the end is to be the retention of God's law in their recollection - " in their mouth," and therefore in their heart, since "out of the abundance of the heart the mouth speaketh."

13:1-10 In remembrance of the destruction of the first-born of Egypt, both of man and of beast, and the deliverance of the Israelites out of bondage, the first-born males of the Israelites were set apart to the Lord. By this was set before them, that their lives were preserved through the ransom of the atonement, which in due time was to be made for sin. They were also to consider their lives, thus ransomed from death, as now to be consecrated to the service of God. The parents were not to look upon themselves as having any right in their first-born, till they solemnly presented them to God, and allowed his title to them. That which is, by special mercy, spared to us, should be applied to God's honour; at least, some grateful acknowledgment, in works of piety and charity, should be made. The remembrance of their coming out of Egypt must be kept up every year. The day of Christ's resurrection is to be remembered, for in it we were raised up with Christ out of death's house of bondage. The Scripture tells us not expressly what day of the year Christ rose, but it states particularly what day of the week it was; as the more valuable deliverance, it should be remembered weekly. The Israelites must keep the feast of unleavened bread. Under the gospel, we must not only remember Christ, but observe his holy supper. Do this in remembrance of him. Also care must be taken to teach children the knowledge of God. Here is an old law for catechising. It is of great use to acquaint children betimes with the histories of the Bible. And those who have God's law in their heart should have it in their mouth, and often speak of it, to affect themselves, and to teach others.And it shall be for a sign unto thee upon thine hand, and for a memorial between thine eyes,.... These are not the words of God or of Moses to the children of Israel, but of an lsraelitish parent to his son, telling him that this feast of unleavened bread would serve the same purpose to refresh his memory with what God did for his people of old, as the tying of a thing on the hand, or placing it before the eye, is to a person to bring anything to his remembrance, to which the allusion is; the like figurative phrases may be observed in Proverbs 1:9, the Jews understand this literally, and hence the use of phylacteries among them, which they bind upon their left hand, and place upon their foreheads between their eyes, of which See Gill on Matthew 23:5, but such a practice could be of no use to answer the end next mentioned:

that the Lord's law may be in thy mouth; for surely this cannot be taken literally, but the sense is, that being instructed by the observance of the above feast, and being taught the meaning of it, they might be able to speak of it to their children, and so transmit it from age to age to their latest posterity:

for with a strong hand hath the Lord brought thee out of Egypt; See Gill on Exodus 13:3.