It was narrated from 'Asim bin 'Umar that his father said:

The Messenger of Allah ﷺ said: “When the night comes from here and the day departs from here, it is time for the fasting person to break his fast,” meaning the east and the west,

حَدَّثَنَا وَكِيعٌ، حَدَّثَنَا هِشَامُ بْنُ عُرْوَةَ، عَنْ أَبِيهِ، عُرْوَةَ عَنْ عَاصِمِ بْنِ عُمَرَ، عَنْ أَبِيهِ، قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ إِذَا أَقْبَلَ اللَّيْلُ وَقَالَ مَرَّةً جَاءَ اللَّيْلُ مِنْ هَهُنَا وَذَهَبَ النَّهَارُ مِنْ هَهُنَا فَقَدْ أَفْطَرَ الصَّائِمُ يَعْنِي الْمَشْرِقَ وَالْمَغْرِبَ‏.‏