Word: cannot in Numbers

And Balaam answered and said unto the servants of Balak, If Balak would give me his house full of silver and gold, I cannot go beyond the word of the LORD my God, to do less or more.

Numbers 23:20

Behold, I have received commandment to bless: and he hath blessed; and I cannot reverse it.

Numbers 24:13

If Balak would give me his house full of silver and gold, I cannot go beyond the commandment of the LORD, to do either good or bad of mine own mind; but what the LORD saith, that will I speak?

Numbers 35:33

So ye shall not pollute the land wherein ye are: for blood it defileth the land: and the land cannot be cleansed of the blood that is shed therein, but by the blood of him that shed it.