Malbim: The verse gives a metaphor. All of a woman's children died, and afterwards she was widowed, without a husband. Afterwards, children come to her from overseas, and say that they are her children. She asks three questions. (a) Who gave birth to these?! I am bereaved [of my children] and alone (a widow)! Also refer to 49:21:3:3, 49:21:4:3.

Rashi: It is lonely.

Radak: It is alone.

Rashi: It is repelled from everyone. Everyone tells me to go away.

Radak: [It is alone] due to children who were exiled, like "k'Eleh Noveles Aleha" (1:30). Surah is an adjective, like "v'Surei ba'Aretz Yikasevu" (Yirmeyah 17:13).

Malbim: Since I was exiled from my place and transient, even if I could have given birth to them, who raised them?

Radak #1: From where are they? Where did they come from?

Radak #2: Where were they?

Malbim: Even if I could have given birth to them, and they raised themselves, who brought them to my place? I was far from them; where did they come from ¹ ? The Nimshal is, Yerushalayim was bereaved; its children were killed or taken captive. It sat alone. Therefore, it was astounded - who gave birth to these children?! It thought that all of them were killed or taken captive. Further, they were exiled for 2,000 years - who raised them, and they did not perish in Galus?!