Rashi: Also this is part of the Kinah (lamentation).

Radak: Initially, Keneses Yisrael were like a fruitful vine with the first kings - David, Shlomo and the good kings after them. Imecha corresponds to Yisrael; the mother is the gathering. Also Yonason translates, when Yisrael do (fulfill) Torah, they are like a vine planted on a source] of water.

Malbim (1, 10): Hashem planted [Yisrael] in the ground - "Kerem Hayah li'Ydidi b'Keren Ben Shamen; ... va'Ykav La'asos Anavim" (Yeshayah 5:1-2). The grapes for which He hoped are Mishpat and Tzedakah. Now it discusses Malchus Tzidkiyah, who was a Tzadik. He is not compared to a tearing lion, rather, to a vine planted in the ground.

Rashi: It is an expression of Dimyon ¹ (comparison). I.e. you are like one who mother was like a vine planted in water.

Radak #2: It is an expression of Dam, [a noun of two letters,] like Tzav and Kav.

Radak citing Rav Hai Gaon: Dam is natural moisture. Anything that comes out of another matter has a moist nature.

Radak: Therefore, it was Poriyah (refer to 19:10:5:2-3) and had long branches, because the water never ceased from under it. So Keneses Yisrael, as long as their leaders were good, it succeeded in its deeds and grew, like a vine on water.

Malbim: Shasul is what was uprooted from its place and replanted elsewhere. He wanted to leave Reshus Nebuchadnetzar to be under Reshus Pharaoh, to be fruitful from much water.

Rashi: This is like "Poreh Rosh" (Devarim 29:17) - it makes fruits.

Radak #1: It grew. This is like Peru u'Rvu. Its grammatical form is like Bochiyah.

Radak #2: It makes many fruits.

Radak: This is an adjective. Its branches were long.

Rashi: It means, via much water.