'Prayer' in the Bible

Howbeit this kind goeth not out but by prayer and fasting.

And said unto them, It is written, My house shall be called the house of prayer; but ye have made it a den of thieves.

And all things, whatsoever ye shall ask in prayer, believing, ye shall receive.

Woe unto you, scribes and Pharisees, hypocrites! for ye devour widows' houses, and for a pretence make long prayer: therefore ye shall receive the greater damnation.