Ma'arif al-Qur'an
Mufti Muhammad Shafiحَتَّىٰ يَبْعَثَ فِي أُمِّهَا رَسُولًا (Unless he sends to their central place a messenger -28:59). Popular meaning of the word 'Umm is mother, and since mother is the very basis of human creation, hence the word 'Umm (اُمَّ ) is also used extensively for origin, base, and foundation. The pronoun ha (translated above as 'their' ) refers back to the towns, and 'mother of the towns' means the central town. The meaning of the verse is that Allah Ta` ala does not destroy a people unless He had sent His message through His messengers in their main cities. When the invitation to truth had reached, and yet people did not accept it, only then the torment is sent on those cities.
This verse has pointed out that Allah's messengers and prophets are generally sent in big cities, and not in smaller towns, because such towns are normally under the influence of big cities, both for their economic and educational needs. If something is known in a big city, it becomes known automatically in the smaller towns around it. Hence, when a prophet is sent in a big city and he starts his call to the truth, the message is spread out in the surrounding towns in no time. This way Allah Ta` ala's message reaches to all and sundry, and if they reject the message of truth, the torment is sent to all of them.
Small towns and villages are subject to the same laws as are applicable to the main cities
As in the case of economic needs, the smaller habitations are dependent on cities, and draw their requirements from there, similarly, when a law or an order is promulgated in the city, it automatically becomes effective in the surrounding towns and villages also. The excuse of having no knowledge of the law is not acceptable.
In the case of sighting of the moon for observing Ramadan and Eids (Shawwal and Dhulhajjah) too, the same principle has been declared by the jurists as applicable. That is, if the evidence of witnesses in the city establishes the sighting of moon, then the people of towns and villages would have to follow the same. But in the case of other cities, it would only apply when the Qadi of that city accepts the evidence and makes the announcement. (Al-Fataw al-Ghayathiyyah)