Appellant brings this appeal from his conviction of four counts of child molestation and raises three enumerations of error.

OCGA 24-9-7 (b) states: "If an objection to competency is known, it shall be taken before the witness is examined at all." Appellant did not object when the assistant district attorney called the seven-year-old girl to the witness stand, nor did he seek to have the trial court examine her after the assistant district attorney completed the preliminary qualifying questions. After the witness was excused from the stand, appellant moved that her testimony be excluded from the record due to her alleged incompetency.

The child testified on direct and cross-examination that she knew right from wrong and that she had to tell the truth when she was in court. Although she said she did not know the meaning of the word "oath," there was sufficient evidence for the trial court to determine that the child met the standard of intelligence required to qualify her as a witness. See Smith v. State, 247 Ga. 511 (277 SE2d 53) (1981).

"The decision of the trial court regarding capacity will not be reversed except for a manifest abuse of discretion." Thomas v. State, 168 Ga. App. 587, 588 (3) (309 SE2d 881) (1983), citing Edwards v. State, 226 Ga. 811, 812 (177 SE2d 668) (1970); Lashley v. State, 132 Ga. App. 427, 429 (208 SE2d 200) (1974). We find no such abuse here.

2. Appellant's second enumeration of error is based on the trial court's failure to charge the jury that it was obliged to consider the age of the child witnesses in judging their credibility. Appellant did not submit a written request to charge on the credibility or competency of the witnesses, and stated that he had no exceptions to the jury charge at its close when so asked by the court.

In the absence of a written request, the trial judge does not ordinarily charge the jury concerning the witnesses' competency, and it is never error for the judge to omit to instruct the jury concerning credibility of a witness. Whitus v. State, 222 Ga. 103, 111 (149 SE2d 130) (1966), revd. on other grounds, 385 U. S. 545 (87 SC 643, 17 LE2d 599) (1967).

3. The last enumeration of error concerns the trial court's restriction of appellant's counsel's closing argument. The court sustained the assistant district attorney's objection to counsel's mention of his grandchildren during his argument. Counsel was instructed to confine his comments to the evidence presented at trial and how it affected appellant.

Although counsel should have ample latitude to argue what has transpired in a case from its inception to its conclusion, the range of such comments is discretionary with the trial judge. Ray v. State, 157 Ga. App. 519 (277 SE2d 804) (1981). It was within the scope of discretion for the trial court to so restrict counsel.