ʿUmar bin Al-Khattab left for Sham, and when he reached a placed called Sargh, he came to know that there was an outbreak of an epidemic (of plague) in Sham. Then ʿAbdurRahman bin ʿAuf told him that Messenger of Allah ﷺ said, "If you hear the news of an outbreak of an epidemic (plague) in a certain place, do not enter that place: and if the epidemic falls in a place while you are present in it, do not leave that place to escape from the epidemic." So ʿUmar returned from Sargh.  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِذَا سَمِعْتُمْ بِأَرْضٍ فَلاَ تَقْدَمُوا عَلَيْهِ وَإِذَا وَقَعَ بِأَرْضٍ وَأَنْتُمْ بِهَا فَلاَ تَخْرُجُوا فِرَارًا مِنْهُ فَرَجَعَ عُمَرُ مِنْ سَرْغَ وَعَنِ ابْنِ شِهَابٍ عَنْ سَالِمِ بْنِ عَبْدِ اللَّهِ أَنَّ عُمَرَ إِنَّمَا انْصَرَفَ مِنْ حَدِيثِ عَبْدِ الرَّحْمَنِ  

That he heard Usama bin Zaid speaking to Saʿd, saying, "Messenger of Allah ﷺ mentioned the plague and said, 'It is a means of punishment with which some nations were punished and some of it has remained, and it appears now and then. So whoever hears that there is an outbreak of plague in some land, he should not go to that land, and if the plague breaks out in the land where one is already present, one should not run away from that land, escaping from the plague."  

أَنَّ رَسُولَ اللَّهِ ﷺ ذَكَرَ الْوَجَعَ فَقَالَ رِجْزٌ أَوْ عَذَابٌ عُذِّبَ بِهِ بَعْضُ الأُمَمِ ثُمَّ بَقِيَ مِنْهُ بَقِيَّةٌ فَيَذْهَبُ الْمَرَّةَ وَيَأْتِي الأُخْرَى فَمَنْ سَمِعَ بِهِ بِأَرْضٍ فَلاَ يَقْدَمَنَّ عَلَيْهِ وَمَنْ كَانَ بِأَرْضٍ وَقَعَ بِهَا فَلاَ يَخْرُجْ فِرَارًا مِنْهُ