Why does it specify the north?
Radak: Most of the exiles are in the north.
Malbim: They are together in the north. From other directions, they are scattered among the nations, and I will need to gather them.
Why does it say "Bam Iver u'Fise'ach"?
Rashi: I will not despise even the feeble ones among them.
Radak: They will come so gently 1 that even the blind and lame among them, and the pregnant and one who gave birth, will go at their slow pace [among them].
Radak citing his father: I will lead them so gently, on such a straight path, that the blind, lame pregnant and Yoledes can go among them, and not stumble.
Malbim: Even places at the ends of the land, that are found there only one blind person and one lame person, just two Yisraelim 2 and they are blemished, i.e. they are few and weak, still I will do a miracle.
Yeshayah 52:12: "You will not leave b'Chipazon." This is unlike Yetzi'as Mitzrayim, which was b'Chipazon (Devarim 16:3). (PF)
This implies that a lone Yisrael would not return. Why didn't Malbim explain that even one blind or lame person will return? (PF)
Why does it say "Harah v'Yoledes Yachdav"?
Radak: Refer to 31:7:2:2-3.
Malbim: The nation will 'become pregnant' and immediately 'give birth', i.e. be a great congregation, as if they were born in one day.