question #1 Sahih al-Bukhari 1875, Book 29, Hadith 9 : What are the implications of migration from Medina to other regions like Yemen, Sham, and Iraq in Islamic history?

I heard Allah’s Messenger (ﷺ) saying, “Yemen will be conquered and some people will migrate (from
Medina) and will urge their families, and those who will obey them to migrate (to Yemen) although
Medina will be better for them; if they but knew. Sham will also be conquered and some people will
migrate (from Medina) and will urge their families and those who will obey them, to migrate (to
Sham) although Medina will be better for them; if they but knew. ‘Iraq will be conquered and some
people will migrate (from Medina) and will urge their families and those who will obey them to
migrate (to ‘Iraq) although Medina will be better for them; if they but knew.”