Read Isaiah 49.
The Messiah speaks to the Gentiles. He calls out, "Listen to me" and "give attention." His message is sharp as a sword. (Compare Hebrews 4:12-13). While, for a time, there were great crowds following Him, ultimately Jesus was rejected. "I have labored in vain" (v.4).
Most of the chapter looks forward to the fulfillment of God's promises to Israel at the second coming of Christ. Then, there will be prosperity and abundance. All world leaders will come and "bow down to you" (v.23). Given the history of Israel since the death of King Solomon to this very day, those promises seem almost unreal. The Jews have been the object of ridicule, scorn and threat by so many world leaders and groups.
But God is committed to keeping His unconditional promises to Abraham (Genesis 12). He "will contend with those who contend with you" (v.25b). When the nation is completely and spiritually restored as people of God, "Then you will know that I am the LORD; those who wait for me shall not be put to shame" (v.23b).
In the meantime, many Jews today feel as if the LORD has forsaken them, that He no longer cares. That sense is in this prophecy. "But Zion said, 'The LORD has forsaken me, my Lord has forgotten me" (v.14) The Apostle Paul asked in Romans 11:1, "Has God rejected his people? By no means!" When Jesus hung on the cross and became sin for us, He experienced that feeling of being forsaken by the Father (Matthew 27:46).
Being rejected and forgotten is a terrible emotion for anyone, but to feel that God has forgotten can be terrifying. Here is Messiah's answer to anyone who feels alone, with unanswered prayers, and alienated from the presence of God.
"Can a woman forget her nursing child, that she should have no compassion on the son of her womb? Even these may forget, yet I will not forget you." And then comes the most powerful statement the Messiah could ever make on this subject, "Behold, I have engraved you on the palms of my hands." (vv.15-16)
The crucifixion of Jesus paid for all sin once and for all. He gave His life for each of us. His promise then is "'I will never leave you nor forsake you.' So we can confidently say, 'The Lord is my helper; I will not fear; what can man do to me.'" (Hebrews 13:5-6)