Keep thyself therefore, and thy soul carefully. Forget not the words that thy eyes have seen, and let them not go out of thy heart all the days of thy life. Thou shalt teach them to thy sons and to thy grandsons,

“ONLY TAKE HEED TO THYSELF etc. LEST THOU FORGET THE THINGS. “[Only] then when you will not forget them and fulfill them in their true form, will you be accounted wise and understanding men; but if you pervert them due to forgetfulness you will be regarded as fools.” This is Rashi’s language. But it is completely incorrect. (take heed), it should be interpreted as a prohibition as will be explained. According to Rashi, however, it is not a prohibition, but a mere negation: if they do not observe the commandments, they will not be considered wise and understanding men. Rather, this verse, in my opinion, is a negative commandment in which he admonishes [us] severely [as follows]: For, as he stated that we should be careful concerning all the commandments and be heedful to perform the statutes and the ordinances, he again stated: “Only I warn you exceedingly to take heed and guard yourselves very, very much to remember whence the commandments came to you, that you should not forget the Revelation on Mount Sinai, nor all the things which your eyes saw there — the thunderings, and the lightnings, His glory and His greatness and His words that you have heard there out of the midst of the fire. And you should convey all the things which your eyes saw at that glorious Revelation unto thy children and thy children’s children forever.” He explained the reason [for this prohibition]: G-d made that Revelation so that you might learn to fear Him all the days and teach your children during all generations. Therefore, do so [remember the Revelation and convey it to your offspring] and do not forget it. Thus before mentioning the commandments which were proclaimed there [on Mount Sinai] he admonished with a negative commandment that we are not to forget a thing from the Revelation [of the Eternal at Mount Sinai], and we are never to remove it from our hearts. He further charged in the form of a positive commandment that we should inform all our children from generation to generation of everything that happened there — what we saw and what we heard., Vol. I, pp. 263-265). To resolve this difficulty we must say that Ramban includes the positive duty in the general commandment of teaching our children the words of the Torah (further 6:7; “The Commandments,” Vol. I, pp. 16-18), which of course includes the narrative of the Revelation. The benefit of this commandment is very great. For if the words of the Torah had come to us only through the mouth of Moses, even though his prophecy was verified with signs and wonders, yet if there [were to] arise in the midst of us a prophet or a dreamer of dreams and he were to command us [to do] the opposite of what the Torah commanded us, and he [were to] give us a sign or wonder, then a doubt would enter the people’s hearts. But since the Torah reaches us from the mouth of the Almighty to our ears, and our eyes behold that there is no intermediary, we will reject anyone who differs and who casts doubt [upon the words of the Torah] and will declare him to be false. No sign will help him, nor will any wonder save him from death at our hands for we know his falsehood. It is this which He stated there [before the Revelation], and they may also believe in thee [Moses] forever, for when we shall also transmit the matter [of the Revelation] to our children they will know that the thing was true without doubt as if all the generations had seen it, for we would not testify falsely to our children to cause them to inherit vanity and things wherein there is no profit, and they will not doubt at all the testimony we will give them. Instead they will believe for a certainty that all of us saw it with our eyes, and likewise [they will believe] all that we told them. This subject will come up again in the section, If there arise in the midst of thee a prophet, or a dreamer of dreams etc. I have already mentioned it there in the section of In the third month.”

“Only take heed to thyself,.... To walk according to this law, and not swerve from it: and keep thy soul diligently; from the transgressions and breaches of it: lest thou forget the things which thine eyes have seen; either the statutes and judgments set before them, and the circumstances of the delivery of them; or the punishment inflicted on the breakers of them; or the favours bestowed on those that observed them: and lest they depart from thy heart all the days of thy life; out of thy mind and memory, and have no place in thy affections, through a neglect and disuse of them: but teach them thy sons, and thy sons' sons; their children and grandchildren, that they may be trained up in them in their youth, and so not depart from them when grown up, and in years; see Deu 6:7.”

“Israel was therefore not to forget the things which it had seen at Horeb with its own eyes. Deu 4:9 "Only beware and take care of thyself." To "keep the soul," i.e., to take care of the soul as the seat of life, to defend one's life from danger and injury (Pro 13:3; Pro 19:16). "That thou do not forget את־הדּברים (the facts described in Ex 19-24), and that they do not depart from thy heart all the days of thy life," i.e., are not forgotten as long as thou livest, "and thou makest them known to thy children and thy children's children." These acts of God formed the foundation of the true religion, the real basis of the covenant legislation, and the firm guarantee of the objective truth and divinity of all the laws and ordinances which Moses gave to the people. And it was this which constituted the essential distinction between the religion of the Old Testament and all heathen religions, whose founders, it is true, professed to derive their doctrines and statutes from divine inspiration, but without giving any practical guarantee that their origin was truly divine. Deu 4:10-12 In the words, "The day (היּום, adverbial accusative) "that thou stoodest before Jehovah thy God at Horeb," etc., Moses reminds the people of the leading features of those grand events: first of all of the fact that God directed him to gather the people together, that He might make known His words to them (Exo 19:9.), that they were to learn to fear Him all their life long, and to teach their children also (יראה, inf., like שׂנאה, Deu 1:27); and secondly (Deu 4:11), that they came near to the mountain which burned in fire (cf. Exo 19:17.). The expression, burning in fire "even to the heart of heaven," i.e., quite into the sky, is a rhetorical description of the awful majesty of the pillar of fire, in which the glory of the Lord appeared upon Sinai, intended to impress deeply upon the minds of the people the remembrance of this manifestation of God. And the expression, "darkness, clouds, and thick darkness," which is equivalent to the smoking of the great mountain (Exo 19:18), is employed with the same object. And lastly (Deu 4:12, Deu 4:13), he reminds them that the Lord spoke out of the midst of the fire, and adds this important remark, to prepare the way for what is to follow, "Ye heard the sound of the words, but ye did not see a shape," which not only agrees most fully with Ex 24, where it is stated that the sight of the glory of Jehovah upon the mountain appeared to the people as they stood at the foot of the mountain "like devouring fire" (Deu 4:17), and that even the elders who "saw God" upon the mountain at the conclusion of the covenant saw no form of God (Deu 4:11), but also with Exo 33:20, Exo 33:23, according to which no man can see the face (פּנים) of God. Even the similitude (Temunah) of Jehovah, which Moses saw when the Lord spoke to him mouth to mouth (Num 12:8), was not the form of the essential being of God which was visible to his bodily eyes, but simply a manifestation of the glory of God answering to his own intuition and perceptive faculty, which is not to be regarded as a form of God which was an adequate representation of the divine nature. The true God has no such form which is visible to the human eye. Deu 4:13 The Israelites, therefore, could not see a form of God, but could only hear the voice of His words, when the Lord proclaimed His covenant to them, and gave utterance to the ten words, which He afterwards gave to Moses written upon two tables of stone (Exo 20:1-14 [17], and Exo 31:18, compared with Exo 24:12). On the "tables of stone," see at Exo 34:1. Deu 4:14 When the Lord Himself had made known to the people in the ten words the covenant which He commanded them to do, He directed Moses to teach them laws and rights which they were to observe in Canaan, viz., the rights and statutes of the Sinaitic legislation, from Ex 21 onwards.”