What is the significance of being Shasul in a good field?
Rashi: The vine did so needlessly, for it was planted in a good field!
Radak: With Nebuchadnetzar, Tzidkiyah had good, honor and success; he was strong, with authority. Why did he rebel and transgress his Shevu'ah?! Had he not done so, he would have made a branch and bore fruits - his children would have lived.
Malbim: Shesilah is uprooting a tree from its place and planting it elsewhere. He wanted to replant the vine in a good field - Egypt. There is much water there. I.e. he wanted to go from Nebuchadnetzar's Reshus to Pharaoh's Reshus, to make a branch and fruits, to be a strong vine, i.e. an independent kingship, and not be subservient to Nebuchadnetzar.
Why does it say "El Sadeh Tov" and "El Mayim Rabim"?
Radak: El is like Al.
What is "Aderes"?
Rashi: It is strong.
