Book 39, Hadith 17

It was narrated that 'Abdullah bin 'Amr said:"A man said: 'O Messenger of Allah! Which emigration (Hijrah) is best?' He said: 'To leave what your Lord, the Mighty and Sublime, dislikes.' He said: 'There are two kinds of emigration, the emigration of the town dweller and the emigration of the Bedouin. As for the Bedouin, when he is called (to fight in Jihad) he must respond, and he must obey when he is commanded, and as for the town dweller, he is the one who is more severely tested and more greatly rewarded