Romans 9:2

That I have great heaviness and continual sorrow in my heart. This is the thing he appeals to Christ for the truth of, and calls in his conscience and the Holy Ghost to bear witness to. These two words, "heaviness" and "sorrow", the one signifies grief, which had brought on heaviness on his spirits; and the other such pain as a woman in travail feels: and the trouble of his mind expressed by both, is described by its quantity, "great", it was not a little, but much; by its quality it was internal, it was in his "heart", it did not lie merely in outward show, in a few words or tears, but was in his heart, it was a heart sorrow; and by its duration, "continual", it was not a sudden emotion or passion, but what had been long in him, and had deeply affected and greatly depressed him: and what was the reason of all this? it is not expressed, but may pretty easily be understood; it was because of the obstinacy of his countrymen the Jews, the hardness of their hearts, and their wilful rejection of the Messiah; their trusting to their own righteousness, to the neglect and contempt of the righteousness of Christ, which he knew must unavoidably issue in their eternal destruction; also what greatly affected his mind was the utter rejection of them, as the people of God, and the judicial blindness, and hardness of heart, he full well knew was coming upon them, and which he was about to break unto them.