It is narrated from Sayyida Umm Sulaym (may Allah be pleased with her) that the Noble Prophet (peace and blessings be upon him) drank water while standing, placing his mouth on a waterskin.
Hadith Referenceسنن دارمي / من كتاب الاشربة / 2161
Sayyiduna Ibn Umar (may Allah be pleased with them both) said: During the blessed era of the Messenger of Allah (peace and blessings be upon him), we used to drink water while standing and eat food while walking.
Hadith Referenceسنن دارمي / من كتاب الاشربة / 2162