Hashem treats Am Yisrael as His Own Flesh, kivyachol. They are the mate of Hakadosh Baruch Hu, and he calls them His daughter, His sister, and His mother.... There is a real closeness between them, and they are His sons, and she’eiris nachalaso – the remainder of His portion – meaning they are like His relatives and His portion.
“How could I punish them,” He says, “for the pain will then be My pain!” as it says, “In all their pain, He has pain” – the Hebrew word “lo” is spelled with an aleph, to show that their pain reaches the peleh ha’elyon, the highest spheres above; and the word is read with a vav, meaning that it is difficult for Hashem to bear their pain and embarrassment, for they are His portion.
(as explained in Tomer Devorah, Chapter 1, the fourth middah)
