'Double edged' in the Bible

"Look, I am making you like a sharp threshing sledge, new and double-edged. You will thresh the mountains and crush them; you will make the hills like straw.

For the word of God is living and active and sharper than any double-edged sword, piercing even to the point of dividing soul from spirit, and joints from marrow; it is able to judge the desires and thoughts of the heart.

He held seven stars in his right hand, and a sharp double-edged sword extended out of his mouth. His face shone like the sun shining at full strength.

"To the angel of the church in Pergamum write the following: "This is the solemn pronouncement of the one who has the sharp double-edged sword: