'Generation' in the Bible

And Jehovah said to Jehu, Because thou hast executed well that which is right in my sight, and hast done unto the house of Ahab according to all that was in my heart, thy children of the fourth generation shall sit on the throne of Israel.

This was the word of Jehovah which he spoke to Jehu saying, Thy sons shall sit upon the throne of Israel unto the fourth generation. And so it came to pass.