Sahih Bukhari Volume 2, Book 24, Hadith Number 532.
Narated By Abu Said Al-Khudri : A Bedouin asked Allah’s Apostle about the emigration. The Prophet (p.b.u.h) said, “May Allah have mercy on you! The matter of emigration is very hard. Have you got camels? Do you pay their Zakat?” The Bedouin said, “Yes, I have camels and I pay their Zakat.” The Prophet said, Work beyond the seas and Allah will not decrease (waste) any of your good deeds.” (See Hadith No. 260 Vol. 5).