'Seven' in the Bible

David was king in Hebron over the people of Judah for seven and a half years.

In Hebron he reigned over Judah for seven years and six months, and in Jerusalem he reigned for thirty-three years over all Israel and Judah.

let seven of his male descendants be turned over to us, and we will execute them before the Lord in Gibeah of Saul, who was the Lord's chosen one." The king replied, "I will turn them over."

He turned them over to the Gibeonites, and they executed them on a hill before the Lord. The seven of them died together; they were put to death during harvest time -- during the first days of the beginning of the barley harvest.

Gad went to David and told him, "Shall seven years of famine come upon your land? Or shall you flee for three months from your enemy with him in hot pursuit? Or shall there be three days of plague in your land? Now decide what I should tell the one who sent me."