Sahih Bukhari | Volume 3 | Hadith Number 284

Narrated by 'Aisha
When Abu Bakr As-Siddiq was chosen Caliph, he said, "My people know that my profession was not incapable of providing substance to my family. And as I will be busy serving the Muslim nation, my family will eat from the National Treasury of Muslims, and I will practise the profession of serving the Muslims."