A judge cannot be allowed to testify in a case on trial before him, and his disqualification therein is absolute. The reasons for this rule are obvious. Imagine the awkward spectacle of a judge passing upon the competency of his own testimony, determining its materiality, if objections are interposed, overruling or sustaining motions of counsel to strike it out of the record, and deciding questions relating to the impeachment of his testimony by other witnesses.