Rashi suggests something different. The Hebrew states, “I will give” an affliction to the house suggesting there is a blessing for the house. The Canaanites who lived in the land hid their treasures in the walls of their homes as they prepared for war with the Israelites who intended to take over their land. Adonai, wanting to give the Israelites a gift, taught them the laws of house-afflictions and the need to tear down the walls. When the Israelite owner tore down the walls of his house, he would discover the hidden treasures.
Niddah is the Hebrew word describing the seven days when a woman is ‘unclean’ during her period and has not completed a mikveh or ritual bath. ‘Unclean’ means being ‘in a state of ritual impurity.’ These seven days are also known as tumah which refers to the period of time when sexual relations between a husband and wife are not to occur. Being ‘ritually impure’ or ‘unclean’ does not mean a woman is in a sinful state or inferior. It is quite the opposite. Scripture emphasizes the holiness inherent in a woman’s cycle to create and nurture a new life within her womb. When as woman is ‘ritually impure,’ it only means she is incapable of conceiving a child.