Romans 10:20
But Esaias is very bold, and saith, I was found of them that sought me not; I was made manifest unto them that asked not after me. But Esaias is very bold, and saith, I was found of them that sought me not; I was made manifest unto them that asked not after me.
Isaiah's declaration is very bold: God would be found by those who did not seek Him and made manifest to those who did not ask after Him. This expresses God's purpose to bring the heathen, those outside Abraham's physical descendants and outside Israel, into number among His people. So brought in, they become recipients of the spiritual blessings promised to Abraham's seed.
What was foretold is that the Gentiles who had not sought God nor called upon His name would find Christ and accept Him as the Redeemer. At the same time Israel, who should have recognized Him first, remained disobedient and rejected Him. Paul himself illustrates this finding, for he was not searching for Christ when Christ revealed to him His worth and righteousness. That revelation led him to count all else as loss in order to gain Christ.