'Thirty' in the Bible

Then brought he me into the outer court; and behold, there were rooms and a pavement, made for the court all around: thirty rooms were on the pavement.

The side rooms were in three stories, one over another, and thirty in order; and they entered into the wall which belonged to the house for the side rooms all around, that they might have hold [therein], and not have hold in the wall of the house.

In the four corners of the court there were courts enclosed, forty [cubits] long and thirty broad: these four in the corners were of one measure.