'Middle' in the Bible

So Gideon and the 100 men with him arrived at the outer perimeter of the encampment at the beginning of the middle watch, just after they had posted sentries. They blew their trumpets and smashed the jars that they were carrying in their hands.

Then Samson grabbed the two middle pillars upon which the house rested and braced himself against them with one pillar in his right hand and the other in his left.