Simply, all the prior decrees of G‑d that were in the foreknowledge of the Creator were decreed in such a way that they have direct causes for their occurrence, and those causes have prior causes.

אֶלָּא שֶׁלְּכָל הַגְּזֵרוֹת הַקּוֹדְמוֹת בִּידִיעַת הַבּוֹרֵא סִבּוֹת, וְלַסִּבּוֹת סִבּוֹת.

However, someone who doesn’t contemplate the manner in which the world is run, when seeing a change in reality, will think that it is the new “cause” that forces a change in reality and their being turned from one matter to another.

וּמִי שֶׁאֵינוֹ מֵבִין עִנְיְנֵי הָעוֹלָם יַחְשׁוֹב, כִּי הַסִּבָּה הַמִּתְחַדֶּשֶׁת מְחַיֶּבֶת שִׁנּוּי הָעִנְיָנִים וְהִתְהַפְּכוּתָם מֵעִנְיָן אֶל עִנְיָן.

In truth, the cause is too weak and insignificant to be themselves the reason for the change or transformation. As can be illustrated from the fact that a single grain of wheat produces three hundred ears, and each ear of grain has thirty grains, so that one grain is therefore the cause for ten thousand grains, or close to that number, to be produced.

וְהַסִּבָּה חֲלוּשָׁה וּנְקַלָּה מִהְיוֹת מִמֶּנָּה שִׁנּוּי אוֹ חִלּוּף בְּעַצְמָם, כַּאֲשֶׁר נִרְאֶה הַגַּרְגִּיר הָאֶחָד מִן הַחִטָּה מַצְמִיחַ שְׁלֹשׁ מֵאוֹת שִׁבֳּלִים, וּבְכָל שִׁבֹּלֶת שְׁלֹשִׁים גַּרְגֵּרִים, וְיִהְיֶה הַגַּרְגִּיר הָאֶחָד סִבָּה לַעֲשֶׂרֶת אֲלָפִים אוֹ קָרוֹב לָהֶם.

Is it not apparent to a person’s mind that the grain itself is too weak to be able to produce such a massive quantity? The same applies to all other seeds that are sown and planted.

הֲיֵעָלֵם כִּי כֹּחַ הַגַּרְגִּיר חָלוּשׁ מֵעֲשׂוֹת כַּמּוּת זוֹ, וְכֵן שְׁאָר הַגַּרְגֵּרִים הַנִּזְרָעִים וְהַנְּטוּעִים.

Similarly, we will say regarding the creation of human beings and other living creatures, which are created from a drop of seed —here too, it is apparent that the drop itself does not have the power to be the source of the entire person. This is also evidenced from the fact that a large fish is created from a small egg of a fish.

וְכֵן נֹאמַר בַּהֲוָיַת הָאָדָם וּשְׁאָר הַחַיִּים מִטִּפַּת הַזֶּרַע, וּכְמוֹ כֵן הֲוָיַת הַדָּג הַגָּדוֹל מִבֵּיצַת הַדָּג עִם קַטְנוּתָהּ.

Although created beings seem to have the power to change the quantity and quality of other created beings, in truth, everything is a result of G‑d’s will. The created beings that seem like the cause of the changes that we witness are merely agents that G‑d uses for that purpose.
It therefore follows that when a person feels stress because of his financial needs and the like, or he overexerts himself in his efforts to provide for himself, it is due to a lack of understanding of G‑d and how He runs the world:

When a person troubles himself with efforts to provide for his financial needs or any other needs, to hasten that which the Creator, may He be exalted, has decreed should be delayed, or to delay that which has been decreed should be hastened, or by trying to produce many of that which has been decreed should be few, or by trying to produce few of that which has been decreed should be many, regarding matters of the world—with the exception of those matters that are necessary for the advancement of observance of mitzvot and the study of Torah— it is due to his weak understanding of the foreknowledge of G‑d, Who knows and has already decided at the beginning of creation all that is going to be. It is also due to a lack of understanding of the inherent goodness in which He conducts himself with the person, because, in truth, everything G‑d does is for the person’s good.

וְטִרְדַּת הַנֶּפֶשׁ לְהַקְדִּים מַה שֶּׁאֵחַר הַבּוֹרֵא יִתְעַלֶּה, וּלְאַחֵר מַה שֶּׁהִקְדִּים, וּלְהַרְבּוֹת מַה שֶּׁהִמְעִיט, וּלְהַמְעִיט מַה שֶּׁהִרְבָּה, מִקִּנְיְנֵי הָעוֹלָם, מִבְּלִי סַבֵּב אֶל קִיּוּם מִצְוַת עֲבוֹדָתוֹ וְקִבּוּל תּוֹרָתוֹ, חֲלִישׁוּת הַהַכָּרָה בַּאֲמִתַּת יְדִיעָתוֹ, וְסִכְלוּת מֵהָבִין טוֹבוֹת הַנְהָגָתוֹ.

If G‑d has decided that a person will have something at a given time, it will come to him at that time without his need to worry or overexert himself. He will not be able to make it happen earlier by exerting himself. Similarly, if it has been decreed that a person will receive a certain amount of money for his livelihood, it is not in his power to change it. Any extra effort a person puts into his livelihood or other needs is due to his lack of understanding of the ways in which G‑d functions, and his lack of belief in G‑d’s inherent goodness.
However, regarding those worldly matters that are necessary for the purpose of learning Torah and the observance of mitzvot, the person is required to make extra effort. This is because when it comes to the service of G‑d, we have the principle that “everything is in the hands of heaven aside from the fear of heaven.” Since G‑d gives a person free choice regarding these matters, it follows that he can, and should, make extra effort in these matters.

It is due to his weak understanding of the foreknowledge of G‑d. Toiling for materialism as if we can change the Divine plan is like opening a bank account but not creating proper means to earn money. Therefore, we must always be aware that the source of everything is G‑d, and that it is His blessing that will make us rich ( Likkutei Sichot, vol. 31, p. 173).

bottom line
You cannot increase or decrease, nor delay or speed-up, that which was decreed by G‑d.

This concept has already been alluded to by the wise man, King Solomon, when he said (Ecclesiastes 3:1): Everything has an appointed season, and there is a time for every matter under heaven . After saying this, he mentions twenty-eight different things that have set times, as he says (ibid. 2): A time to give birth and a time to die , until the end of his list, when he says (ibid. 8): A time for war and a time for peace. Similarly, he says (ibid. 9:11): For time and fate will overtake them all.

וּכְבָר רָמַז הֶחָכָם אֶל הָעִנְיָן הַזֶּה בְּמַאֲמָרוֹ "לַכֹּל זְמָן וְעֵת לְכָל חֵפֶץ תַּחַת הַשָּׁמָיִם" (קהלת ג, א), וְאַחַר כָּךְ זָכַר מֵהֶם עֶשְׂרִים וּשְׁמוֹנָה עִנְיָנִים, וְהוּא מַה שֶׁאָמַר "עֵת לָלֶדֶת וְעֵת לָמוּת" עַד אָמְרוֹ "עֵת מִלְחָמָה וְעֵת שָׁלוֹם" (שם ג, ב־ח), וְאָמַר "כִּי עֵת וָפֶגַע יִקְרֶה אֶת כֻּלָּם" (קהלת ט, יא),

These verses are cited as support that a person is not able to hasten that which has been decreed to be delayed or vice versa, because everything has an appointed season.

He also says (ibid. 5:7): For the Highest over the high waits, and there are higher ones over them.

וְאָמַר "כִּי גָבֹהַּ מֵעַל גָּבֹהַּ שׁוֹמֵר וּגְבֹהִים עֲלֵיהֶם" (קהלת ה, ז).

This is cited as support that although we perceive the causes of events in a certain way, in truth, those causes have higher causes, and ultimately everything has been preordained by G‑d.

The ways in which the Creator upholds His decrees are too hidden, deep, and lofty for us to understand even part of them. All the more so are we not capable of understanding all of them. The verse already says (Isaiah 55:9): As the heavens are higher than the earth, so are My ways higher than your ways and My thoughts higher than your thoughts.

וַהֲלִיכוֹת דִּינֵי הַבּוֹרֵא יִתְעַלֶּה יוֹתֵר נַעֲלָמוֹת וַעֲמֻקּוֹת וְעֶלְיוֹנוֹת מֵהַגִּיעַ אֶל יְדִיעַת חֶלְקֵיהֶן, כָּל שֶׁכֵּן כְּלָלָן. וּכְבָר אָמַר הַכָּתוּב "כִּי גָבְהוּ שָׁמַיִם מֵאָרֶץ, כֵּן גָּבְהוּ דְרָכַי מִדַּרְכֵיכֶם וּמַחְשְׁבוֹתַי מִמַּחְשְׁבוֹתֵיכֶם" (ישעיה נה, ט).

Although there appear to be changes in nature, it cannot be said that G‑d “changed His mind,” so to speak. Rather, at the beginning of creation, He decided that nature would change according to His decision at that time. As support for this supra-rational concept, the author quotes the verse, So are My ways higher than your ways and My thoughts higher than your thoughts.

For us to understand even part of them. For if we were to understand Him (His ways), we would be Him ( Marpei Lanefesh ).