'Thirty' in the Bible

Then brought he me into the outer court; and, lo, there were chambers and a pavement, made for the court round about: thirty chambers were upon the pavement.

And the side-chambers 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-chambers round about, 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 inclosed, forty cubits long and thirty broad: these four in the corners were of one measure.