Thou shalt teach them diligently - שננתם shinnantam, from שנן shanan, to repeat, iterate, or do a thing again and again; hence to whet or sharpen any instrument, which is done by reiterated friction or grinding. We see here the spirit of this Divine injunction. God's testimonies must be taught to our children, and the utmost diligence must be used to make them understand them. This is a most difficult task; and it requires much patience, much prudence, much judgment, and much piety in the parents, to enable them to do this good, this most important work, in the best and most effectual manner. See at the end of this chapter, Deuteronomy 6:25 (note).

And shalt talk of them when thou sittest in thine house - Thou shalt have religion at home, as well as in the temple and tabernacle.

And when thou walkest by the way - Thou shalt be religious abroad as well as at home, and not be ashamed to own God wheresoever thou art.

When thou liest down, and when thou risest up - Thou shalt begin and end the day with God, and thus religion will be the great business of thy life. O how good are these sayings, but how little regarded!

And thou shall teach them diligently unto thy children,.... Care and diligence are to be used, and pains taken, to instruct children, as soon as they are capable, in the knowledge of God, and of his commandments; that they are to love him, fear him, serve, and worship him; this is to bring them up in the nurture and admonition of the Lord, Ephesians 6:4, it may be rendered "thou shalt whet or sharpen them" (s), the words or commandments; it is expressive of diligence and industry in teaching, by frequent repetition of things, by inculcating them continually into their minds, endeavouring to imprint them there, that they may be sharp, ready, and expert in them:

and shalt talk of them when thou sittest in thine house; at the time of meals, or at leisure hours, or even when employed in any business in the house which will admit of it; every opportunity should be taken to instil the knowledge of divine things into their tender minds:

and when thou walkest by the way; in a journey, and any of his children with him; or for diversion, in the garden, field, or vineyard; occasion may be taken on sight of any of the works of creation to lead into a discourse concerning God, his nature, perfections, and works, and the obligations his creatures lie under to love, fear, and serve him: and when thou liest down, and when thou risest up; at the time of going to bed, and rising from it; which, as they are seasons of prayer to God, may be improved in instruction of children.

(s) "et acues ea", Vatablus, Piscator.

And thou shalt {c} teach them diligently to thy children, and shalt talk of them when thou sittest in thy house, and when thou walkest by the way, and when thou liest down, and when thou risest up. {teach: Heb. whet, or, sharpen}

(c) Some read, You shall whet them upon your children: that is, that they may imprint them more deeply in their memory.

6:7 Teach them diligently - Heb. whet, or sharpen them, so as they may pierce deep into their hearts. This metaphor signifies the manner of instructing them, that it is to be done diligently, earnestly, frequently, discreetly.

teach: Heb. whet, or, sharpen

6:6-16 Here are means for maintaining and keeping up religion in our hearts and houses. 1. Meditation. God's words must be laid up in our hearts, that our thoughts may be daily employed about them. 2. The religious education of children. Often repeat these things to them. Be careful and exact in teaching thy children. Teach these truths to all who are any way under thy care. 3. Pious discourse. Thou shalt talk of these things with due reverence and seriousness, for the benefit not only of thy children, but of thy servants, thy friends and companions. Take all occasions to discourse with those about thee, not of matters of doubtful disputation, but of the plain truths and laws of God, and the things that belong to our peace. 4. Frequent reading of the word. God appointed them to write sentences of the law upon their walls, and in scrolls of parchment to be worn about their wrists. This seems to have been binding in the letter of it to the Jews, as it is to us in the intent of it; which is, that we should by all means make the word of God familiar to us; that we may have it ready to use upon all occasions, to restrain us from sin, and direct us in duty. We must never be ashamed to own our religion, nor to own ourselves under its check and government. Here is a caution not to forget God in a day of prosperity and plenty. When they came easily by the gift, they would be apt to grow secure, and unmindful of the Giver. Therefore be careful, when thou liest safe and soft, lest thou forget the Lord. When the world smiles, we are apt to make court to it, and expect our happiness in it, and so we forget Him who is our only portion and rest. There is need of great care and caution at such a time. Then beware; being warned of your danger, stand upon your guard. Thou shalt not tempt the Lord thy God; neither by despairing of his power and goodness, while we keep in the way of our duty; nor by presuming upon it, when we turn aside out of that way.