We were with Allah's Messenger (ﷺ) on a journey, and when the sun set, he said to a man, "Get down and
prepare a drink of Sawiq for me." The man said, "O Allah's Messenger (ﷺ)! Will you wait till it is evening?"
Allah's Messenger (ﷺ) again said, "Get down and prepare a drink of Sawiq." The man said, "O Allah's
Apostle! Will you wait till it is evening, for it is still daytime. " The Prophet (ﷺ) again said, "Get down
and prepare a drink of Sawiq." So the third time the man got down and prepared a drink of sawiq for
him. Allah's Messenger (ﷺ) drank thereof and pointed with his hand towards the East, saying, "When you see
the night falling from this side, then a fasting person should break his fast."
Sahih al-Bukhari Book 68, Hadith 46