Umar bin Khattab was informed, while traveling on the road to Sham, that the Prophet ﷺ had said, "This sickness was a punishment inflicted upon nations before you. When you hear of it in a land, do not enter it, and when it breaks out in a land where you are, do not leave fleeing from it."So Umar bin Khattab turned back from Sham.
حدثنا حجاح ويزيد المعنى قالا أخبرنا ابن أبي ذئب عن الزهري عن سالم عن عبد الله بن عامر بن ربيعة أن
أخبر عمر بن الخطاب وهو يسير في طريق الشام عن النبي ﷺ قال إن هذا السقم عذب به الأمم قبلكم فإذا سمعتم به في أرض فلا تدخلوها عليه وإذا وقع بأرض وأنتم بها فلا تخرجوا فرارا منه قال فرجع عمر بن الخطاب من الشام
Its isnad is sahih, see 1666, 1679. This is how it appears in the manuscripts in this narration, Zuhri from Salim from Abdullah bin Amir bin Rabia, and it will come later at 1682 through the route of Malik from Zuhri from Abdullah bin Amir, with no mention of Salim in it, and that is the correct version, Allah willing, and it is what is found in the Muwatta, as will come later. Salim bin Abdullah bin Umar has no narration from Abdullah bin Amir, rather Zuhri narrates from both of them. I fear that the addition of Salim in this isnad is an error on the part of the copyists.Al-saqam, with two fathas, or with a damma then sukun, its root meaning is illness, and what is meant here is plague.