'Seven' in the Bible

The period of David's kingship in Hebron lasted seven years and six months.

He reigned over Judah for seven years and six months in Hebron, and he reigned over all of Israel including Judah for 33 years in Jerusalem.

is to have seven of his sons turned over to us. We will hang them in the presence of the LORD at Gibeah, which belonged to Saul, whom the LORD chose."

Then he turned them over to the custody of the Gibeonites, who hanged them on the mountain in the presence of the LORD. All seven of them died at the same time. They were executed during the first days of harvest, just as the barley began to be gathered in.

So Gad went to David and asked him, "Shall seven years of famine come to your land, or three months of reversals while you flee from your enemies as they pursue you, or three days of pestilence in your land? Decide right now what I am to answer to the one who sent me."