A.T. Robertson Commentary Romans 9:2

"that I have great sorrow and unceasing pain in my heart." — Romans 9:2 (ASV)

Sorrow (λυπη). Because the Jews were rejecting Christ the Messiah. "We may compare the grief of a Jew writing after the fall of Jerusalem" (Sanday and Headlam).

Unceasing pain in my heart (αδιαλειπτος οδυνη τη καρδια). Like angina pectoris. Οδυνη is old word for consuming grief, in N.T. only here and and 1 Timothy 6:10.

Unceasing (αδιαλειπτος). Late and rare adjective (in an inscription 1 cent. B.C.), in N.T. only here and 2 Timothy 1:3. Two rare words together and both here only in N.T. and I and II Timothy (some small argument for the Pauline authorship of the Pastoral Epistles).