'Anguish' in the Bible

But all these things are merely the beginning of birth pangs [of the intolerable anguish and the time of unprecedented trouble].

And at that time the sign of the Son of Man [coming in His glory] will appear in the sky, and then all the tribes of the earth [and especially Israel] will mourn [regretting their rebellion and rejection of the Messiah], and they will see the Son of Man coming on the clouds of heaven with power and great glory [in brilliance and splendor].