Miriam's Well

Had no water: From here [we learn that] all forty years they had the well in Miriam’s merit.

(2) ....On the tenth of (Nisan) Miriam died and her well disappeared....

So the well, which was with Israel in the wilderness, was like a rock of the size of a k'bara, and was oozing out and rising as from the mouth of this flask, travelling with them up the mountains and going down with them to the valleys. Wherever Israel encamped it encamped opposite them before the door of the Tabernacle. The princes of Israel with their slaves surrounded it, and said over it this song, "Spring up, O well, sing to it." Then the waters bubbled forth, and rose on high like a pillar; and every one drew out the staff of their tribe and family, as it is said, "The well which the princes digged, Which the nobles of the people delved, With the sceptre and with their staves...." The waters which emptied themselves from it became a great river, pouring themselves into the Mediterranean, and bringing back from there all the precious things of the world, as it is said, "These forty years the ADONAI your God has been with you; you lacked nothing."

(3) and the mouth of the well: The well of Miriam that went with Israel in the wilderness on all of the journeys. And some say, that it opened its mouth and uttered song, as it stated (Numbers 21:17), "rise up, O well; answer it."

At that time also ‎the waters they drank in the desert due to the merit of Miriam, ‎will assume the taste of any liquid they will fancy.‎ ‎

R. Yossi son of R. Judah says: Three good leaders had arisen for Israel, namely Moses, Aaron and Miriam, and for their sakes three good things were conferred [upon Israel], namely, the Well, the Pillar of Cloud, and the Manna.

The Well -- for the merit of Miriam;

The Pillar of Cloud --for the merit of Aaron;

The Manna -- for the merit of Moses.

When Miriam died the well disappeared, as it is said, "And Miriam died there," and immediately follows [the verse], "And there was no water for the congregation...."

translation by Soncino

"And there was not water for the congregation"

The people lacked water as a punishment because they did not mourn for her appropriately. The text tells us about Moses's and Aaron's deaths "the Children of Israel wept for them," and here, (in the story of Miriam's death), it doesn't say "they wept for her," and it does say, "She died there and they buried her there." In the place that she died, that will be her burial place forever, and she was forgotten as dead from the heart, and they did not feel her absence at all. Therefore, they lacked the water so that they should know retroactively that the well existed because of the merit of Miriam.