R. Elazar Hamodai offered a different explanation for what made Yithro rejoice. It was not the manna, he argued, but the miraculous well — the portable spring of water that traveled with the Israelites through the desert.
And like the manna, the well was no ordinary water source. The people described their experience of it in extraordinary terms: "In the well that the Lord has given us, we savor the taste of old wine, of new wine, of milk, of honey, of all the sweets in the world." Water that tasted like aged wine. Water that tasted like fresh honey. Whatever the drinker desired, the well provided.
R. Elazar Hamodai drew this interpretation from the same escalating phrase that R. Yehoshua had used, but applied it to a different miracle. The verse says Yithro rejoiced over "good," then "the good," then "all the good," then "over all the good" — four levels of increasing wonder. A well that contained every flavor of sweetness within its waters justified this fourfold expression of joy.
The rabbinic tradition often associated this well with Miriam, Moses' sister, and taught that it accompanied Israel on her merit. When she died, the well dried up (Numbers 20:1-2). That a single source of water could contain the taste of every drink in the world was, for R. Elazar Hamodai, the specific "good" that overwhelmed Yithro with gladness.