Bnei Yisrael sustained above nature

ובמדרש תרומה אתם צאני ואני הרועה.

And in the Midrash (on parshas Terumah): "You are My flock and I am the Shepherd."

The Sefas Emes brings a Midrash in which Hashem describes His relationship to Bnei Yisrael through three images — flock and shepherd, vineyard and watchman, sons and father.

עשו דיר לרועה שיבוא וירעה אתכם.

"Make a pen for the Shepherd, that He may come and tend you."

The Mishkan is the "pen" that Bnei Yisrael build so that Hashem, the Shepherd, will dwell among them and provide for them.

אתם הכרם עשו סוכה לשומר שישמור אתכם.

"You are the vineyard; make a booth for the Watchman, that He may guard you."

As a vineyard needs a watchman's booth, so Bnei Yisrael build a dwelling for Hashem so that He will guard them.

אתם בנים עשו בית לאב שידור אצל בניו כו'

"You are sons; make a house for the Father, that He may dwell beside His children."

And as children build a home for their father, so Bnei Yisrael make a Mishkan so that Hashem, as a Father, will reside among His children.

והענין כנ"ל כי הקב"ה בחר לבנ"י להיות כל צרכיהם מאתו ית' שלא בדרך הטבע.

And the matter is as above: that Hashem chose Bnei Yisrael for all their needs to come from Him, not by way of nature.

The common thread of all three images is that Bnei Yisrael are meant to receive everything directly from Hashem, above the ordinary channels of teva (nature).

כאשר ראינו כי האמהות היו עקרות להיות כל בנ"י בדרך נס.

As we have seen that the Imahos (Matriarchs) were barren, so that all of Bnei Yisrael would come into being by way of a miracle.

The very founding of the nation was supernatural: Sarah, Rivkah and Rachel were barren, so that Klal Yisrael's existence rests on open nes (miracle) rather than nature.

וכמו כן עבדים היינו.

And likewise, "we were slaves."

So too the bondage in Mitzrayim was part of this pattern, lifting Bnei Yisrael's existence out of the natural order.

וימררו את חייהם.

"And they embittered their lives."

The Egyptians embittered their lives — yet this very suffering served to detach the chiyus (life-force) of Bnei Yisrael from natural means.

כדי להיות בני חיי ומזוני של בנ"י בדרך נס כמ"ש לעיל.

So that the children, life, and sustenance (bnei, chayei, u'mezonei) of Bnei Yisrael would be in a miraculous way, as written above.

Through the barrenness and the bondage, the three fundamentals of life — offspring, lifespan, and livelihood — were established for Bnei Yisrael along a miraculous track rather than a natural one.

לכן תהלוכות בנ"י בעוה"ז בדרך מקרה.

Therefore the ways of Bnei Yisrael in this world appear to go "by way of happenstance."

Because their true source is supernatural, in olam hazeh Bnei Yisrael seem to lack a fixed natural standing, as though their affairs run by chance.

ועיקר מהותם בעולם העליון.

And the essence of their being is in the upper world.

Their real mahus (essence) belongs to the higher, spiritual realm, not to this world of nature.

עשו דיר שיבוא וירעה הוא בחי' מזוני ה' רועי.

"Make a pen, that He may come and tend" — this is the aspect of mezonei (sustenance): "Hashem is my Shepherd."

The Sefas Emes now maps the three Midrashic images onto the three fundamentals. The Shepherd tending His flock corresponds to mezonei, livelihood — "Hashem is my Shepherd, I shall not lack" (Tehillim 23:1).

סוכה וישמור הוא חיי.

"A booth, that He may guard" — this is chayei (life).

The watchman who guards the vineyard corresponds to chayei, life itself, which Hashem protects.

בית לאב בחי' בני:

"A house for the Father" — the aspect of bnei (children).

And the father dwelling among his children corresponds to bnei, offspring — the supernatural gift of children to Bnei Yisrael.

Summary: The Midrash's three images — Shepherd and flock, Watchman and vineyard, Father and sons — all teach that Bnei Yisrael receive everything from Hashem above nature. From the barren Imahos to the bondage in Mitzrayim, the nation's very existence was forged by nes, so its essence lies in the upper world; the three images correspond precisely to the three miraculous fundamentals of bnei, chayei, u'mezonei — children, life, and sustenance.