Pour water. He poured water on his head and Abu Ayyub moved his head with his hands. He carried his hands forward and backward. He then said I saw him doing similarly. (Using translation from Abū Dāʾūd 1840)   

مَنْ هَذَا؟ فَقُلْتُ أَنَا عَبْدُ اللهِ بْنُ حُنَيْنٍ أَرْسَلَنِي إِلَيْكَ عَبْدُ اللهِ بْنُ عَبَّاسٍ لِيَسْأَلَكَ كَيْفَ كَانَ رَسُولُ اللهِ ﷺ يَغْسِلُ رَأْسَهُ وَهُوَ مُحْرِمٌ؟ قَالَ فَوَضَعَ أَبُو أَيُّوبَ يَدَهُ عَلَى الثَّوْبِ فَطَأْطَأَهُ حَتَّى بَدَا لِي رَأْسُهُ ثُمَّ قَالَ لِإِنْسَانٍ يَصُبُّ عَلَيْهِ اصْبُبْ فَصَبَّ عَلَى رَأْسِهِ ثُمَّ حَرَّكَ رَأْسَهُ بِيَدَيْهِ فَأَقْبَلَ بِهِمَا وَأَدْبَرَ ثُمَّ قَالَ هَكَذَا رَأَيْتُهُ ﷺ يَفْعَلُ لَفْظُ حَدِيثِ الْقَعْنَبِيِّ  

[Machine] Omar ibn Al-Khattab, by Allah, pouring more water on hair only makes it more tangled. So, he invoked Allah and poured it onto his head.  

عُمَرُ بْنُ الْخَطَّابِ ؓ وَاللهِ مَا يَزِيدُ الْمَاءُ الشَّعْرَ إِلَّا شَعَثًا فَسَمَّى اللهَ ثُمَّ أَفَاضَ عَلَى رَأْسِهِ  

[Machine] To me, 'Umar ibn Al-Khattab, come, let me compete with you in holding our breaths underwater to see which one of us can hold their breath longer, even though we are forbidden.  

لِي عُمَرُ بْنُ الْخَطَّابِ ؓ تَعَالَ أُبَاقِيكَ فِي الْمَاءِ أَيُّنَا أَطْوَلُ نَفَسًا وَنَحْنُ مُحْرِمُونَ  

[Machine] It is said that Aasim ibn Umar and Abdul Rahman ibn Zaid were swimming in the sea, and they were taking turns submerging each other's heads under water. Umar was watching them, and he did not criticize their actions.  

أَنَّ عَاصِمَ بْنَ عُمَرَ وَعَبْدُ الرَّحْمَنِ بْنُ زَيْدٍ وَقَعَا فِي الْبَحْرِ يَتَمَاقَلَانِ يُغَيِّبُ أَحَدُهُمَا رَأْسَ صَاحِبِهِ وَعُمَرُ يَنْظُرُ إِلَيْهِمَا فَلَمْ يُنْكِرْ ذَلِكَ عَلَيْهِمَا