Pirkei Avoth 5:5 Midrash: Kohelet Rabbah & Vayikra Rabbah

Another matter, “all the rivers go to the sea,” all Israel assembles only in Jerusalem and ascends [there] at the times of the festivals each and every year. “Yet the sea is not full,” but Jerusalem is never full, as we learned: “They stand crowded, but prostrate themselves with ample space” (Avot 5:5). Rabbi Shmuel bar Ḥova said in the name of Rabbi Aḥa: There were four cubits of space between each and every one, and a cubit on every side, so that one would not hear the prayer of another and become confused.⁴⁸There were four cubits for each person when they would prostrate themselves, and one cubit between each person when they prayed (Midrash HaMevoar). “To the place that the rivers go” – to the place that Israel assembles in this world, there they will assemble in the World to Come in the future, as it is stated: “It will be on that day, that a great shofar will be sounded; and the lost in the land of Assyria, and the dispersed in the land of Egypt will come and worship the Lord on the holy mountain in Jerusalem” (Isaiah 27:13).

“And the bull of the sin offering, and the two rams” (Leviticus 8:2), Rav Huna said in the name of Rabbi Abba bar Kahana: He fashioned a hill of sorts; a ram on one side, a ram on the other side, and a bull in the middle.²⁹The different heights of the animals produced the effect of a hill. This symbolized the fact that Aaron and his sons were becoming exalted through the process of investiture on these days (Etz Yosef).
“Assemble the entire congregation at the entrance of the Tent of Meeting” (Leviticus 8:3).
“Assemble the entire congregation at the entrance of the Tent of Meeting.” Rabbi Elazar said: All of Israel was six hundred thousand, and you say: “At the entrance of the Tent of Meeting”? Rather, this is one of the places where the lesser contained the greater.³⁰A large number of people were able to gather in a relatively small area.
Similarly, “Let the water under the heavens be gathered to one place” (Genesis 1:9). The way of the world is that a person empties a full vessel into an empty vessel. Or, is it, perhaps, a full vessel into a full vessel? The entire world was full of water, and you say: “Let the water…be gathered”? Rather, this is one of the places where the lesser contained the greater.
Similarly, “take for yourselves cupped handfuls of soot of a furnace” (Exodus 9:8). Rav Huna said: This cupped handful and this clenched handful are not comparable. The cupped handful is twice the clenched handful. Four cupped handfuls are eight clenched handfuls. The outcome is that the cupped hand of Moses holds eight clenched handfuls.³¹Two handfuls for Moses and two handfuls for Aaron are altogether four cupped handfuls. But it says that “Moses shall throw it heavenward.” In order to do so powerfully, he must use one hand. Rather, it teaches that the Holy One blessed be He provided the ability. [Moses and] Aaron took cupped handfuls, and Moses threw them. And you say: “Moses threw then heavenward” (Exodus 9:8) all at once. Rather, this is one of the places where the lesser contained the greater.
Similarly, “The length of the courtyard shall be one hundred cubits and the width shall be fifty on each side” (Exodus 27:18). Rabbi Yosei bar Ḥalafta said: The length of the courtyard was one hundred cubits and all of Israel was standing inside it? Rather, this is one of the places where the lesser contained the greater.
Similarly, “Moses and Aaron gathered the assembly together before the rock” (Numbers 20:10). Rav Ḥanin said: It was the size of a sieve and all of Israel was standing before it? Rather, this is one of the places where the lesser contained the greater.
Similarly, “Joshua said to the children of Israel: Come here” (Joshua 3:9). Rav Huna said: He stood them all erect between the two staves of the Ark. Rabbi Ḥama bar Ḥanina said: He arranged them between the two staves of the Ark. Rava said: He crowded them between the two staves of the Ark. That is what is written: “Joshua said: With this you will know that the living God is in your midst” (Joshua 3:10). He said to them: Because the two staves of the Ark contained you, I know that His Divine Presence is in your midst.
This occurred in the Temple, too, as we learned: They would stand crowded and prostrate themselves spaced.³²Mishna Avot 5:5. Rabbi Shmuel bar Ivya said in the name of Rabbi Aḥa: There were four cubits between each and every one, and a cubit on each side so that none of them would hear the voice of another praying.
This will occur in the future, too, as it is stated: “At that time, they will call Jerusalem the Throne of the Lord, and all the nations will be gathered to it” (Jeremiah 3:17). Rabbi Yoḥanan ascended to inquire after the wellbeing of Rabbi Ḥanina and found him engaged in this verse: “At that time, they will call Jerusalem the Throne of the Lord, and all the nations will be gathered to it.” He said to him: ‘Will it [Jerusalem] contain them?’ He said to him: ‘The verse says: “Expand the place of your tent” (Isaiah 54:2) “for you will spread right and left”’ (Isaiah 54:3).