The Sages have said:

posted by admin on Fri, 02/10/2017 - 16:39

Does not atonement come through the blood, as it is said: For it is the blood that maketh atonement by reason of the life!

— Babylonian Talmud
Babylonian Talmud, Yoma 5a referring to Vayikra (Lev.) 17:11 in the Tanakh

The Sages have said:

posted by admin on Fri, 02/10/2017 - 16:38

What is the cause of the mourning (Zechariah 12:10)? It is well according to him who explains that the cause is the slaying of Messiah, the son of Joseph, as it is written, 'And they shall look upon me whom they have pierced; and they shall mourn for him as one mourneth for his only son.'

— Babylonian Talmud
Babylonian Talmud, Sukkah 52a