The Messenger of Allah ﷺ as saying: The difference between our fasting and that of the people of the Book is eating shortly before dawn. (Using translation from Abū Dāʾūd 2343)
قَالَ رَسُولُ اللهِ ﷺ إِنَّ فَصْلَ مَا بَيْنَ صِيَامِنَا وَصِيَامِ أَهْلِ الْكِتَابِ أَكْلَةُ السَّحَرِ