'Thirty' in the Bible

And the days in which we came from Kadesh-barnea, until we were come over the brook Zered, were thirty and eight years; until all the generation of the men of war were consumed from the midst of the camp, as Jehovah sware unto them.

And the children of Israel wept for Moses in the plains of Moab thirty days: so the days of weeping in the mourning for Moses were ended.