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, Eph 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.