Don’t obstruct. That was the message from three top Democrats to President Donald Trump on Sunday.

In a joint statement, Reps. Elijah Cummings, Adam Schiff and Jerrold Nadler warned Trump against efforts to “discourage, intimidate or otherwise pressure” his former personal attorney, Michael Cohen, who has agreed to publicly testify Feb. 7 before the House Oversight Committee.

“The integrity of our process to serve as an independent check on the Executive Branch must be respected by everyone, including the President. Our nation’s laws prohibit efforts to discourage, intimidate, or otherwise pressure a witness not to provide testimony to Congress,” the statement read. “The President should make no statement or take any action to obstruct Congress’ independent oversight and investigative efforts, including by seeking to discourage any witness from testifying in response to a duly authorized request from Congress.”

The statement came in response to Trump’s appearance on Saturday night on Fox News, when he told Jeanine Pirro that Cohen “should give information maybe on his father-in-law, because that’s the one that people want to look at.”

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Trump added: “Because where does that money – that’s the money in the family. And I guess he didn’t want to talk about his father – he’s trying to get his sentence reduced. So, it’s pretty sad."

When Pirro asked for Cohen’s father-in-law’s name, Trump answered, “I don’t know, but you’ll find out, and you’ll look into it because nobody knows what’s going on over there.”

Cummings, Schiff and Nadler are prominent Democratic chairmen, of the House Committees on Oversight and Reform, Intelligence and Judiciary, respectively.

In December, Cohen was sentenced to three years in prison for what U.S. District Court Judge William Pauley called a “veritable smorgasbord of fraudulent conduct.” He took the blame in court, citing his “blind loyalty to the man that caused me to choose the path of darkness.”

Known as Trump’s longtime fixer, Cohen has acknowledged arranging hush money payments before the 2016 election to two women, adult film star Stormy Daniel and former Playboy model Karen McDougal, who claimed affairs with Trump. He has implicated Trump in the payments, saying he made them at his direction.

In a statement after agreeing to testify, Cohen said, “I look forward to having the privilege of being afforded a platform with which to give a full and credible account of the events which have transpired.”