'Plague' in the Bible

If you refuse to let them go, behold, I will plague all your borders with frogs:

Yahweh said to Moses, "Yet one plague more will I bring on Pharaoh, and on Egypt; afterwards he will let you go. When he lets you go, he will surely thrust you out altogether.

The blood shall be to you for a token on the houses where you are: and when I see the blood, I will pass over you, and there shall no plague be on you to destroy you, when I strike the land of Egypt.

"When you take a census of the children of Israel, according to those who are numbered among them, then each man shall give a ransom for his soul to Yahweh, when you number them; that there be no plague among them when you number them.