Hadith: On taking a ritual bath from Janābah (major ritual impurity), the Messenger of Allah (may Allah's peace and blessings be upon him) used to wash his hands and perform ablution like that for prayer, then wash himself

عَنْ عَائِشَةَ أُمِّ المؤمنين رضي الله عنها قَالَتْ:
كَانَ رَسُولُ اللَّهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ إِذَا اغْتَسَلَ مِنَ الجَنَابَةِ، غَسَلَ يَدَيْهِ، وَتَوَضَّأَ وُضُوءَهُ لِلصَّلاَةِ، ثُمَّ اغْتَسَلَ، ثُمَّ يُخَلِّلُ بِيَدِهِ شَعَرَهُ، حَتَّى إِذَا ظَنَّ أَنَّهُ قَدْ أَرْوَى بَشَرَتَهُ، أَفَاضَ عَلَيْهِ المَاءَ ثَلاَثَ مَرَّاتٍ، ثُمَّ غَسَلَ سَائِرَ جَسَدِهِ، وَقَالَتْ: كُنْتُ أَغْتَسِلُ أَنَا وَرَسُولُ اللَّهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ مِنْ إِنَاءٍ وَاحِدٍ، نَغْرِفُ مِنْهُ جَمِيعًا.
[صحيح] - [رواه البخاري] - [صحيح البخاري: 272]

‘Ā’ishah, the Mother of the Believers, (may Allah be pleased with her) reported:
On taking a ritual bath from Janābah (major ritual impurity), the Messenger of Allah (may Allah's peace and blessings be upon him) used to wash his hands and perform ablution like that for prayer, then wash himself. He would, then, run his wet hand through his hair until he would feel that his skin had become wet. Then, he would pour water thrice over it, and then wash the rest of his body. She further said: I and the Messenger of Allah (may Allah's peace and blessings be upon him) used to bathe from a single container from which we used to take water simultaneously.
[Authentic hadith] - [Narrated by Bukhari] - [Sahih Bukhari - 272]

Explanation

On taking a ritual bath from Janābah, the Prophet (may Allah's peace and blessings be upon him) would start washing his hands. Then, he would make Wudū’ (ablution) as he would for prayer. Then, he would pour water over his body. Then, he would run his wet hands through his hair, and when feeling that water had reached the roots of the hair and had wetted the skin, he would pour the water thrice over his head, then, he would wash the rest of his body. ‘Ā’ishah (may Allah be pleased with her) said: I and the Messenger of Allah (may Allah's peace and blessings be upon him) used to bathe from a single container from which we would take water simultaneously.