'Fast' in the Bible

Be it known unto the king, that we went into the province of Judea, to the house of the great God, which is builded with great stones, and timber is laid in the walls, and this work goeth fast on, and prospereth in their hands.

Then I proclaimed a fast there, at the river of Ahava, that we might afflict ourselves before our God, to seek of him a right way for us, and for our little ones, and for all our substance.