ENOfficial
It was narrated from Yahya bin Sa'eed who heard Sa'eed bin Al-Musayyab say: "Thaqif welcomed 'Umar with a drink. He called for it, but when he brought it close to his mouth, he did not like it. He called for water to weaken it, and said: 'Do like this.'"
Source: sunnah.com
Other translations
Arabic
أَخْبَرَنَا زَكَرِيَّا بْنُ يَحْيَى، قَالَ حَدَّثَنَا عَبْدُ الأَعْلَى، قَالَ حَدَّثَنَا سُفْيَانُ، عَنْ يَحْيَى بْنِ سَعِيدٍ، سَمِعَ سَعِيدَ بْنَ الْمُسَيَّبِ، يَقُولُ تَلَقَّتْ ثَقِيفٌ عُمَرَ بِشَرَابٍ فَدَعَا بِهِ فَلَمَّا قَرَّبَهُ إِلَى فِيهِ كَرِهَهُ فَدَعَا بِهِ فَكَسَرَهُ بِالْمَاءِ فَقَالَ هَكَذَا فَافْعَلُوا .
sunnah.com