What is the definition of "Eid"?
Rashi and Seforno: It was a mist. (A cloud 1 - Targum Onkelos; a cloud of glory - Targum Yonasan.)
Yerushalmi Ta'anis, 3:3: It has connotations of 'breaking' 2 - because it 'breaks' those who store grain in the summer in order to force the prices up.
See Torah Temimah, citing Sukah 11b, and Torah Temimah, note 19.
Torah Temimah: As in Iyov 18:13.
What exactly happened when the mist came up from the ground and watered the ground? What function did this watering serve?
Rashi: Hashem brought the mist from the deep, 1 with which He watered the clouds. The clouds, in turn, soaked the ground, producing the mud (clay) from which Hashem formed Adam 2 - like a baker who adds water to the dough and them kneads it into a dough. 3
Targum Yonasan: The "Eid" was a cloud of glory that descended from underneath Hashem's Kisei ha'Kavod and drew water from the ocean before rising and watering the earth.
Gur Aryeh: But perhaps the mist arose from the ocean? The Pasuk states, "A mist arose from the earth" (not from the oceans); this refers to the depths below the earth.
Moshav Zekenim asks why we do not find that the mist kneaded the earth to produce animals. He answers that they were created through Ma'amar (speech), but man, through Asiyah (action).
Why did the mist water the land now - as soon as the world was created?
Rosh Hashanah 11a: Because that was when the earth needed rain - To teach us that the world was created in Tishri. 1
What is the significance of the fact that the mist that watered the land ascended from the earth, and did not descend from the sky?
QUESTIONS ON RASHI
Rashi writes: "A mist arose - This relates to the creation of man." But perhaps the verse means that a mist arose to irrigate the ground and plants?
Gur Aryeh: The preceding verse (2:5) already informed us that it would not rain until after man had been created, since there was no one to appreciate it (Rashi to 2:5).