What is the interpretation of the saying of Imam Ali, may God be pleased with him: "Woman is entirely evil, and the worst of her is that she is indispensable," and how does this saying accord with Islam's honoring of women in the Quran and Sunnah?

The questioner is correct in his objection to the unqualified description of evil being attributed to women. The book Nahj al-Balagha cannot be reliably attributed to Amir al-Mu'minin Ali, may Allah be pleased with him. A righteous woman is not evil; rather, she is the best provision of this world and a source of happiness for the son of Adam. Islam has honored women and lifted humiliation from them. As for the emergence of the horn of Satan from Najd, this is true, and it carries severe condemnation for the fabricators among the people of innovation, because most of them are from the East. Najd is the desert of Iraq and what lies beyond it to the East, from the perspective of the people of Medina.