".. say to those who prophesy from their own inspiration, ‘Hear the word of the Lord! Thus says the Lord God, “Woe (judgment is coming) to the foolish prophets who are following their own spirit [claiming to have seen things] but have [in fact] seen nothing."

~ Ezekiel 13.2-3 AMP

Chapter 13 talks about whitewashed wall.

God speaks through people. And these people ought not make claims that God does not specifically make through them.

Do not think God said "this and that" through that person, so I can make the same claim. If God does not tell me so, no I cannot.

Speak as God says. No less and no more.

Related: Whitewashed tombs