Certainly, those of the house of Israel must have felt like the Lord had forsaken them, given all the tribulation and persecution to which they were subjected. Nephi makes reference to one of these persecutions in the next chapter, 'they shall be scattered among all nations and shall be hated of all men… the Lord God will raise up a mighty nation among the Gentiles, yea, even upon the face of this land; and by them shall our seed be scattered' (1 Nephi 22:5,7). Their assumption, that the Lord had forgotten them, was incorrect. They, of course, had forgotten the Lord.
"This poetic passage provides yet another reminder of Christ's saving role, that of protective, redeeming parent to Zion's children. He comforts his people and shows mercy when they are afflicted, as any loving father or mother would toward a child, but, as Nephi here reminds us through Isaiah, much more than any mortal father and mother could do. Although a mother may forget her sucking child (as unlikely as any parent might think that could be), Christ will not forget the children he has redeemed or the covenant he has made with them for salvation in Zion. The painful reminders of that watch care and covenant are the marks of the Roman nails graven upon the palms of his hands, a sign to his disciples in the Old World, his Nephite congregation in the New World, and to us in latter-day Zion that he is the Savior of the world and was wounded in the house of his friends." (Christ and the New Covenant: The Messianic Message of the Book of Mormon [Salt Lake City: Deseret Book Co., 1997], 84.)
"The Lord is going to comfort Zion; He is going to have mercy upon her afflicted ones. But Zion said, 'The Lord hath forsaken me, and my Lord hath forgotten me.' 'Can a woman forget her sucking child?' saith the Lord. 'Yea, she may forget, but I will not forget thee. Behold, I have graved thee upon the palms of my hands; thy walls are continually before me.' This refers to the building up of Zion in the last days; the gathering together of the people, preparatory to the coming of the Son of Man." (Brian H. Stuy, ed., Collected Discourses, 5 vols. [Burbank, Calif., and Woodland Hills, Ut.: B.H.S. Publishing, 1987-1992], vol. 1, Oct. 6, 1889)