'Thirty' in the Bible

The Philistines fought, and Israel was struck, and they fled every man to his tent: and there was a very great slaughter; for there fell of Israel thirty thousand footmen.

Samuel took Saul and his servant, and brought them into the guest room, and made them sit in the best place among those who were invited, who were about thirty persons.

He numbered them in Bezek; and the children of Israel were three hundred thousand, and the men of Judah thirty thousand.

The Philistines assembled themselves together to fight with Israel, thirty thousand chariots, and six thousand horsemen, and people as the sand which is on the seashore in multitude: and they came up, and encamped in Michmash, eastward of Beth Aven.