Why is a husband allowed to abstain from his wife for one hundred nights without sinning, while the angels curse a wife if she abstains from her husband for a single night?

A husband may travel for six months or less without his wife's permission. He is not permitted to travel for more than that period except with her permission. This differs from abandoning the marital bed, which is only permissible for a legitimate reason, such as the wife's rebellion (nushooz). The husband must engage in sexual intercourse with his wife according to her needs.