"I said: 'O Messenger of Allah! I am woman with tight braids on my head, should I undo it to perform Ghusl for Janabah? He said: 'No. It is sufficient that you only pour three scoops of water (with hands held together) over your head, then pour water over the rest of your body, to be purified.'" Or he said: "Then you will be purified."  

قُلْتُ يَا رَسُولَ اللَّهِ إِنِّي امْرَأَةٌ أَشُدُّ ضَفْرَ رَأْسِي أَفَأَنْقُضُهُ لِغُسْلِ الْجَنَابَةِ قَالَ لاَ إِنَّمَا يَكْفِيكِ أَنْ تَحْثِينَ عَلَى رَأْسِكِ ثَلاَثَ حَثَيَاتٍ مِنْ مَاءٍ ثُمَّ تُفِيضِينَ عَلَى سَائِرِ جَسَدِكِ الْمَاءَ فَتَطْهُرِينَ أَوْ قَالَ فَإِذَا أَنْتِ قَدْ تَطَهَّرْتِ