'Oh' in the Bible

And Gideon said unto him, Oh, my lord, if Jehovah is with us, why then is all this befallen us? and where are all his wondrous works which our fathers told us of, saying, Did not Jehovah bring us up from Egypt? but now Jehovah hath cast us off, and delivered us into the hand of Midian.

And he said unto him, Oh, Lord, wherewith shall I save Israel? behold, my family is the poorest in Manasseh, and I am the least in my father's house.

Then Manoah entreated Jehovah, and said, Oh, Lord, I pray thee, let the man of God whom thou didst send come again unto us, and teach us what we shall do unto the child that shall be born.