What are "Chevlei Yoledah"?
Radak: Pain like birth contractions. Malbim - the verse depicts the pains that come upon the nation like birth contractions that come upon a Yoledes. The more that the pains increase, there is more hope that the fetus will leave the womb and the contractions will cease. "Ki Va'u Vanim Ad Mashber v'Cho'ach Ayin Leledah" (Yeshayah 37:3). Normally, based on many contractions it seems that the fetuses came to the Mashber and they will be born soon. However, the mother lacks strength to expel them from her womb.
In what way is he not Chacham?
Radak: Because the afflictions are compared to birth contractions, it says that those born are not wise. The future generations, who saw their fathers afflicted due to their sins, they were not Chachamim, and did not contemplate to understand this. They did not repent from their fathers' deeds, and did evil like them.
Malbim: He does not know to leave the womb at the time of birth and stand on the Mashber - this is where fetuses stand, and are saved to leave and be born. He stays in the womb like a Nefel (stillborn baby).
Malbim (according to the metaphor): At the time when the nation will be born, they already had birth contractions from many afflictions. They did not stand on the Mashber (repent), which is the way to birth. It said before this "Tzarur Avon Efrayim" (12) - the sin is like excess blood in the womb that does not allow the fetus to be born. So the sin blocked them from Teshuvah and being born, even though the mother was close to birth and screaming in her contractions.
Why does it say "Es Lo Ya'amod"?
Rashi: An affliction comes to him in which he cannot bear and endure.
Radak: If he were a Chacham, he would not stand for a while in the Mishbar. He would quickly leave it, and go outside to the world. Some babies are zealous from birth, to leave the womb quickly. So too, if they were Chachamim, they would not remain in affliction. They would immediately repent, and be saved from the affliction!
Malbim (according to the Nimshal): The afflictions became great, and it seems that it is time for the nation to leave the straits and be born - to be saved via Hashem. This is birth of the nation! However, the mother lacks strength to expel the fetus, i.e. Mitzvos and good deeds via which the nation is born to be Bnei Kel Chai.
What is "b'Mishbar Banim"?
Rashi: It is the birth stool. She sits on it to give birth.
Radak: It is the womb. It is called so due to the birth contractions and afflictions she has while the fetus is in the womb and cannot leave quickly.
