'Thirty' in the Bible

Thirty-eight years had gone by from the time when we came away from Kadesh-barnea till we went over the stream Zered; by that time all the generation of the men of war among us were dead, as the Lord had said.

For thirty days the children of Israel were weeping for Moses in the table-lands of Moab, till the days of weeping and sorrow for Moses were ended.