Exodus 7:25
Seven full days passed after the Lord struck the Nile.
Exodus 8:9-10
Moses said to Pharaoh, "You may have the honor over me -- when shall I pray for you, your servants, and your people, for the frogs to be removed from you and your houses, so that they will be left only in the Nile?"
Exodus 10:23
No one could see another person, and no one could rise from his place for three days. But the Israelites had light in the places where they lived.
2 Samuel 24:13
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."