OPINION ON APPELLANT’S PETITION FOR DISCRETIONARY REVIEW
MILLER, Judge.A jury convicted appellant of the murder of his estranged wife, finding he used a deadly weapon, a gun, in the commission of this offense. The jury also assessed appellant’s punishment at 99 years imprisonment in the Texas Department of Corrections 1 and a $5,000 fine. On direct appeal, the court of appeals, in an unpublished opinion, abated the appeal and remanded the cause to the trial court for a retrospective competency trial. Hensarling v. State, No. 09-88-281-CR, delivered January 24, 1990. After the competency hearing, in which the jury found appellant was competent to stand trial in 1988, appellant appealed and raised four points of error complaining of error in the conduct of the hearing. The court of appeals overruled these points and affirmed the judgment of the trial court in another unpublished opinion. Hensarling v. State, No. 09-88-281 CR, delivered December 19, 1990. We granted appellant’s petition on three grounds for review, to-wit: (1) the court of appeals erred in holding that the judgment as to competency was not manifestly unjust; (2) the court of appeals erred in holding that the trial judge, who presided over appellant’s murder trial, was not disqualified as a witness under Tex.R.Crim.Evid. 605 at the competency hearing; and (3) the court of appeals erred in holding appellant failed to preserve error as to the trial judge’s refusal to grant three challenges for cause during voir dire in the murder trial.2
We now find that our decision to grant appellant’s petition for discretionary review on the first and third grounds for review, listed above, was improvident. Tex.R.App. Proc. 202(k). That part of appellant’s petition is therefore dismissed. Just as in any case where this Court refuses to grant a petition for discretionary review, our decision to dismiss this portion of appellant’s petition as improvidently granted should not be construed as approval of the court of appeals’ opinion. Walker v. State, 811 S.W.2d 131 (Tex.Crim.App.1991). We will address, however, the merits of appellant’s second ground for review and affirm the judgment of the court of appeals on that basis. A limited review of the facts is necessary for our disposition.
*170Appellant was convicted of murder in a jury trial on September 7, 1988. The trial was held in the 159th Judicial District Court with the Honorable David Walker presiding. On direct appeal from his conviction, the court of appeals abated appellant’s appeal and remanded the cause to the trial court for a retrospective competency hearing pursuant to Art. 46.02, V.A.C.C.P. In the meantime, Judge Walker had retired from the bench and the Honorable Gerald Goodwin was appointed to replace him as presiding judge of the 159th District Court. Judge Goodwin, however, had been the prosecuting attorney in appellant’s murder trial in 1988. Consequently, the competency hearing was transferred to the 217th Judicial District Court where the Honorable David Wilson presided.
Appellant’s first competency hearing began on April 9, 1990, with Judge Wilson presiding over the proceedings. On April 12,1990, after seven hours of jury deliberations, Judge Wilson declared a mistrial in this cause. Subsequently, a second competency hearing was held on April 30, 1990, and this jury returned a verdict on May 2, 1990. The jury found appellant was not incompetent to stand trial in September of 1988.
Judge Walker, who presided over appellant’s criminal trial, testified without objection at appellant’s retrospective competency hearing. On appeal, appellant complained the trial court erred in allowing Judge Walker to testify at the competency hearing in violation of Tex.R.Crim.Evid. 605.3 In briefly addressing this contention, the court of appeals stated:
The purpose of [Rule 605] is to prevent the impartial referee of the trial from placing his seal of approval on one side in the eyes of the jury. See Brown v. Lynaugh, 843 F.2d 849 (5th Cir.1988). We hold Rule 605 does not apply because Judge Walker was not the presiding judge at the competency hearing. Point of error one is overruled.
Hensarling, slip op. at p. 2.
In his brief before this Court, appellant asserts his due process rights were violated by the allowance of Judge Walker’s testimony at the competency hearing. Appellant argues that permitting this testimony “allowed the State to reap a direct benefit from Judge Walker’s error in not holding a timely competency hearing” and that if a timely hearing had been held, i.e., before the criminal trial on the merits4, Rule 605 would have prohibited Judge Walker from testifying at the hearing. Appellant thus contends Rule 605 should be made applicable to retrospective competency hearings. We find appellant’s contention without merit.
The Texas Rules of Criminal Evidence were promulgated by this Court and became effective September 1, 1986. Rule 605 states in full:
RULE 605. COMPETENCY OF JUDGE AS WITNESS
The judge presiding at the trial may not testify in that trial as a witness. No objection need be made in order to preserve the point.
The language of Rule 605 is unambiguous, and construing this rule according to rules of grammar and common usage leads to only one interpretation of the rule. The phrase “the judge presiding at the trial may not testify in that trial” means that the judge who is presiding over a proceeding may not “step down from the bench” and become a witness in the very same proceeding over which he is currently presiding. Rule 605 addresses only that specific situation; the rule does not encompass any future proceedings in which the judge is participating but not over which the *171judge is presiding. Moreover, this narrow interpretation of Rule 605 accomplishes the objective of this rule. The judge is a neutral arbiter in the courtroom, and the rule seeks to preserve his posture of impartiality before the parties and particularly in the eyes of the jury. Learned commentators have noted some of the problems inherent in allowing a judge to be a witness in a trial over which he is presiding, to-wit:
A judge who testifies, for example, might be required to evaluate his own testimony in the course of deciding a motion for a directed verdict. Furthermore, the aura of impartiality surrounding the judge will likely cause the jury to give undue credence to his testimony. Opposing counsel might well be hesitant to attack the judge on cross-examination for fear of alienating either the judge or jury. Finally, practical problems inhere in such judicial testimony. Who, for example, will rule on objections?
See Goode, Wellborn and Sharlot, Texas Rules of Evidence: Civil and Criminal, 33 Texas Practice § 605.1, p. 384 (footnotes omitted).
In the present cause, Judge Wilson presided over the competency hearing in which Judge Walker was a witness. Under these facts, we hold there was no error under Rule 605. Appellant’s second ground for review is overruled.
The judgment of the court of appeals is therefore affirmed.
CLINTON, J., dissents to dismissal of grounds 1 and 3, and joins the judgment of affirmance.. Now called the Texas Department of Criminal Justice — Institutional Division.
. The court of appeals addressed the issue in this third ground for review in their opinion on January 24, 1990.
. No preservation of error problem is presented in this cause because Rule 605 expressly states “[n]o objection need be made in order to preserve the point."
. The record reflects appellant filed two motions requesting the trial judge to conduct a hearing to determine appellant’s competency to stand trial. The trial judge conducted a hearing in accordance with Art. 46.02, § 2, V.A.C.C.P., and after the hearing refused to impanel a jury to determine appellant's competency. As noted, the court of appeals remanded this cause to the trial court to impanel a jury to determine whether appellant was competent to stand trial at the time of his criminal trial in 1988.