Musar do Powtórzonego Prawa 4:15

And he who does not guard himself from everything that destroys his body, finds that he is an enemy to himself, seeks his own evil, and will be judged [for it]. For if one harms others, the sin is in his hands, and how much more so if he injures himself. And “he who troubles his own flesh is cruel”(Proverbs 11:17). And even more so one needs to guard himself from a place which has even the slightest risk of mortal danger. And if he enters a dangerous place for money, it turns out that his wealth is dearer to him than his life, and if a miracle is performed for him, it depletes his merits. And it turns out that he sells his merits and great goodness stored up for him in the world to come, exchanging the reward of mitzvot for money, which perishes and is destroyed. Further, he will surely be punished. And he is liable [to forfeit] his life as the words of the Merciful One warned: “Guard yourself and guard your body greatly (Deuteronomy 4:9), and guard your souls greatly (Deuteronomy 4:15)”. Therefore, no man should go to a dangerous place, such as on dangerous roads or through seas and rivers, unless it is absolutely necessary for his livelihood. And [in these cases] he should bring with him armed men in order to minimize the danger through natural means. And if he can go on dry land, he should not go by river or sea, which increase the danger. And proportional to the danger, one loses merit if a miracle is performed. And therefore all that one is able to do to minimize danger with money or extra effort, behold, such a person [who does this things] is zealous and will be rewarded, and the reward is greater than the expenditure. And the commandment to take utmost care of yourselves which he fulfills is sufficient to save him from all distresses and bring blessings upon his home. And he will remain intact in his body and intact in his wealth (and more is written on this in the section titled “Guarding”).

And we also need to understand and know that the Creator, may He be blessed, does not have a body nor physicality, an image, or any appearance, as it is stated, you heard the sound of words but perceived no image; nothing but a voice (Deuteronomy 4:12). And it states, To whom, then, can you liken God, what form compare to Him (Isaiah 40:18). And it likewise states, "To whom, then, can you liken Me, to whom can I be compared," says the Holy One (Isaiah 40:25). And even though we have found many verses in which physical words are written about the Creator, may He be blessed — such as the matter that is stated, The eyes of the Lord are everywhere (Proverbs 15:3); My own hand founded the earth (Isaiah 48:13); under His feet there was the likeness of a pavement of sapphire (Exodus 24:10); written with the finger of God (Exodus 24:10); and many verses like these — they were only written to make people understand what they are able to understand. And about what is similar to this, the sages, may their memory be blessed, have said, "The Torah speaks in the language of people." So it is all appellations and metaphors regarding the Creator. But the central truth is that He is without a body or physical image. And we have been much warned in the Torah to distance ourselves from it, from physicalizing, like the matter that is stated, [So you are to take exceeding care for your selves], for you did not see any image (Deuteronomy 4:15).

Perhaps you will say: behold we see that the sages everywhere obligated a man to guard himself well and not put himself in danger even if he is a righteous person with many merits. For instance: "everything is in the hands of heaven except colds and heatstrokes" (Ketubot 30a) and the Torah says "you shall guard yourselves very carefully" (Devarim 4:15). Hence one should not decide to "trust in G-d" in all situations, and in the Talmud Yerushalmi (Berachot 3, see also Chulin 142a) they said: "even when performing a Mitzva!".