Allah, the Exalted, says,
(And) This is an introduction to that which is implied, "Verily, We sent."
(to Thamud) They were a group of people who were living in cities carved from the rocks, between Tabuk and Al-Madinah (in Arabia). They lived after the people of `Ad, so Allah sent to them,
(their brother Salih.) He (Salih) commanded them to worship Allah alone. He said to them,
(He brought you forth from the earth) This means: `He began your creation from it (the earth). From it He created your father, Adam.'
(and settled you therein,) This means: `He made you prosperous in the earth. You are settled in it and you treasure it.'
(then ask forgiveness) `This is in reference to your previous sins. '
(and turn to Him in repentance.) `This is in reference to the future.'
(Certainly, my Lord is Near (to all by His knowledge), Responsive.) This is similar to Allah's statement,
(And when My servants ask you concerning Me, then (answer them), I am indeed Near (to them by My knowledge). I respond to the invocations of the supplicant when he calls on Me.) 2:186