The President tells The Washington Post he doesn't want aides to testify before various Democratic-controlled congressional committees

Of course. Because the president doesn't tell the truth about anything. So, aids testifying under oath before Congress might put him in jail or get him impeached. It makes complete sense to me. If aids refuse to testify it could put them in jail for contempt of Congress which is a minimum of 1 month in jail and 100,000 dollars in fines.
begin quote from:The President tells The Washington Post he doesn't want aides to testify before various Democratic-controlled congressional committees