It is narrated from Sayyiduna Abu Ayyub al-Ansari (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The five prayers, and from one Friday to the next, and the fulfilment of the trust, are an expiation for what is between them." I said: What is the fulfilment of the trust? He (peace and blessings be upon him) said: "The ritual bath (ghusl) for major impurity (janabah), for beneath every hair there is the effect of janabah."
Hadith Referenceالمعجم الكبير للطبراني / باب الخاء / 3974