New Revised Standard Version
For by now I could have stretched out my hand and struck you and your people with pestilence, and you would have been cut off from the earth.

Contemporary English Version
In fact, he could already have sent a terrible disease and wiped you from the face of the earth.

New American Bible
For by now I should have stretched out my hand and struck you and your people with such pestilence that you would have vanished from the earth.

Douay-Rheims Bible
For now I will stretch out my hand to strike thee, and thy people, with pestilence, and thou shalt perish from the earth.

For now I will stretch out my hand to strike thee, and thy people, with pestilence, and thou shalt perish from the earth.

stretch

Exodus 9:3,6,16 Behold my hand shall be upon thy fields; and a very grievous murrain upon thy horses, and asses, and camels, and oxen, and sheep. . . .

Exodus 3:20 For I will stretch forth my hand, and will strike Egypt with all my wonders which I will do in the midst of them: after these he will let you go.

that

Exodus 11:4-6 And he said: Thus saith the Lord: At midnight I will enter into Egypt: . . .

Exodus 12:29,30 And it came to pass at midnight, the Lord slew every firstborn in the land of Egypt, from the firstborn of Pharao, who sat on his throne, unto the firstborn of the captive woman that was in the prison, and all the firstborn of cattle. . . .

cut off

Exodus 14:28 And the waters returned, and covered the chariots and the horsemen of all the army of Pharao, who had come into the sea after them, neither did there so much as one of them remain.

1 Kings 13:34 And for this cause did the house of Jeroboam sin, and was cut off, and destroyed from the face of the earth.

Proverbs 2:22 My son, forget not my law, and let thy heart keep my commandments.