Israel's Past (Ezekiel 36:16-20).
‘Moreover the word of Yahweh came to me saying, “Son of man, when the house of Israel dwelt in their own land, they defiled it by their way and by their doings. Their way before me was as the uncleanness of a woman in her separation.”
The blood that was poured out through violence is here likened to a woman's menstrual flow. The menstrual flow of blood was looked on with something akin to horror by the Israelite male. According to the Law it rendered the woman ‘unclean' (Leviticus 15:19-24), so that anyone who touched her was unclean. So here the defiling of the land by their behaviour could be looked on as similar to the menstrual discharge. It rendered the land unclean before God, as ‘unholy', and therefore not touchable by Him. Thus God withdrew in horror and kept apart. (The menstrual flow was presumably used as an example because the behaviour of the people included the wrongful spilling of blood).