عَنْ أَبِي سَعِيدٍ رَضِيَ اللَّهُ عَنْهُ أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ نَهَى عَنْ اخْتِنَاثِ الْأَسْقِيَةِ
It is narrated from Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) forbade bending the mouth of a water-skin upwards and drinking water from the inside.