Devarim 4: 9-10
It is a positive commandment to take care of ourselves. Its not a prohibitive statement against damaging oneself but I think its common sense that doing so is negative and doing so is also in violation of this warning.
You know, something sounds odd about your interpretation of Deut. 4.9 (i.e. about health): it's as if G-d sends a man (i.e. a prophet) in a place, and when that man steps out of his house, G-d tells him "take care!". I hope such a situation does sound odd to everybody. And I think the reason for that is that it's man's natural instinct to seek his welfare.
About my interpretation of Deut 4.9, that you said:
You can't even pinpoint what exactly the prohibition is. Look what you wrote: "it's a "take heed not to make yourself idols" thing. It's not about health."
First of all, it's not a prohibition because it commands to do something. (Ie, it's a positive commandment, not a negative commandment - Look at the language).
It's not a "'take heed" not to make idols thing' because that's not "a thing." Is it take heed of something? Or is it don't make idols? Refraining from making idols is an actual action. What do you mean take heed? We already have the prohibition against idol worship, and every time it is said, it is said very much UNLIKE this current expression in Devarim 4:9.
Sorry, I was a bit in a hurry, and perhaps I didn't say it properly.
First, let's see the verses:
7. For what great nation is there that has G-d so near to it, as the Lord our G-d is at all times that we call upon Him?
8. And which great nation is it that has just statutes and ordinances, as this entire Torah, which I set before you this day?
9. But beware and watch yourself very well, lest you forget the things that your eyes saw, and lest these things depart from your heart, all the days of your life, and you shall make them known to your children and to your children's children,
10. the day you stood before the Lord your G-d at Horeb, when the Lord said to me, "Assemble the people for Me, and I will let them hear My words, that they may learn to fear Me all the days that they live on the earth, and that they may teach their children.
11. And you approached and stood at the foot of the mountain, and the mountain burned with fire up to the midst of the heavens, with darkness, a cloud, and opaque darkness.
12. The Lord spoke to you out of the midst of the fire; you heard the sound of the words, but saw no image, just a voice.
13. And He told you His covenant, which He commanded you to do, the Ten Commandments, and He inscribed them on two stone tablets.
14. And the Lord commanded me at that time to teach you statutes and ordinances, so that you should do them in the land to which you are crossing, to possess.
15. And you shall watch yourselves very well, for you did not see any image on the day that the Lord spoke to you at Horeb from the midst of the fire.
16. Lest you become corrupt and make for yourselves a graven image, the representation of any form, the likeness of male or female,
.....
1. Look at the context and see that it has nothing to do with physical health. The context talks about a totally different subject.
2. It seems that the commandment to "watch yourself" is
repeated in verse 15. In verse 9 we are told to watch ourselves
because, but doesn't get to say
about what you should watch yourself. Instead, the focus is put in what happened, which
must be related to the commandment to "watch yourself". And this would make the interpreted "health" commandment sound odd, because it would mean that one should be commanded to keep himself healthy
because G-d appeared on the mountain,
because He spoke to the people from the fire,
because He gave them the Ten Commandments, etc. - it just doesn't make sense this way.
3. Instead, the focus of the context is the
keeping of the commandments that were given. So "watch yourself" is meaningful because one must be
careful to keep the commandments and must be
careful not to fall (e.g. by making idols). And the focus is also put on "watch yourself" not to make yourself idols,
because, as the context suggests, G-d did not appear in a human form, so that people would not make any image of Him, and to strengthen His commandment to people not to make and not to worship any idol (perhaps I am not wrong if I understand idol as "a material representation of someone (e.g. G-d, angel, "saint", etc.), for worship").