It is narrated from Sayyidah Aishah (may Allah be pleased with her) that in the time of the Prophet (peace and blessings be upon him) a woman began to have istihadah (irregular bleeding), and she was ordered. I asked (Abdur Rahman bin al-Qasim): Was it the Prophet (peace and blessings be upon him) who ordered her? He said: I am not narrating anything to you from the Prophet (peace and blessings be upon him). Then she (Aishah) said: "She was ordered to delay Zuhr and pray Asr early and perform one ritual bath (ghusl) for both of them; and to delay Maghrib and pray Isha early and perform one ghusl for both of them; and to perform one ghusl for the morning prayer."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحيض / 1654