What is the meaning of "Hechesheisi me'Olam"?
Rashi: This is many days that I was silent about Churban of My house. Will I forever be silent?!
Radak: Hashem says, for a long time I was silent about the pain of Yisrael in Galus. I held back about the suffering of their pressure, like one who restrains and does not show to others what is in his heart. He hides his desire, like "va'Yis'apak va'Yomer Simu Lachem" (Bereishis 43:11), "va'Yis'apak Haman" (Esther 5:10).
Malbim: Just like I was never silent from the [first] days of the world from avenging those who anger Me 1 , so I will not be silent now.
Avos 5:2: We learn Hashem's patience from the 10 generations from Adam until No'ach (they angered Him, until He brought the flood), and from the 10 generations from No'ach until Avraham (they angered Him, until Avraham came and received their reward). (Perhaps Malbim means that Hashem always avenges, even if it is a long time later. - PF)
Why does it say "ka'Yoledah Ef'eh"?
Rashi: Until now, My Ru'ach pained Me. From now and onwards, I will scream like a woman giving birth. Radak - so I will scream about the Resha'im, who are My enemies. I restrained too long; I cannot bear their pain any more.
Malbim: The verse depicts that the anger In His stomach filled His stomach with something tangible, like a Yoledes.
What is the meaning of "Eshom"?
Rashi: I will be confounded.
Radak: I will swallow or destroy.
Malbim: I will exhale. (A Yoledes breathes very quickly - she exhales and inhales at once, amidst pressure of the inner Ru'ach.)
What is "v'Esh'af"?
Rashi: I will desire to destroy everything together - all My enemies.
Radak: I will swallow all My enemies together. This is like "Ki She'afani Enosh" (Tehilim 56:2), "Sha'afah Ru'ach" (Yirmeyah 2:24).
Malbim: I will exhale. Refer to 42:14:3:3.