Is it necessary to perform ghusl (ritual bathing) after menstruation for the validity of fasting once it has ceased?

Neglecting the ritual bath (ghusl) after menstruation does not invalidate the fast. This is the view of the majority of jurists, who hold that there is no difference whether the delay in performing ghusl is intentional or unintentional. Their evidence for this is by analogy with the state of janabah (major ritual impurity requiring ghusl), as it is authentically reported from Aisha (may Allah be pleased with her) that the Prophet (peace and blessings of Allah be upon him) said to someone who woke up in a state of janabah and intended to fast: "And I wake up in a state of janabah, and I intend to fast, so I perform ghusl and fast."