The testimony of a witness concerning a particular matter is inadmissible unless he has personal knowledge of the matter. (Evid. Code, sec. 702.) In this case appellant was convicted of continuous sexual abuse of D. On appeal he claimed that trial attorney was prejudicially deficient by failing to object to Rosalie’s testimony that L told her that appellant had been touching D since she was 4 years old, so as to establish the requisite time period for violation of Penal Code section 288.5. Appellant asserted that L had no personal knowledge of the act. Resorting to federal law, the court noted that the rationale for requiring a hearsay declarant to have personal knowledge when the declarant’s statement is offered for its truth is identical to the rationale for requiring a witness to have personal knowledge of the subject matter of the witness’s testimony – in the absence of personal knowledge, the factfinder is put in the position of determining the truth of a statement without knowledge of its source and with no means of evaluating the reliability of the source of the information. Agreeing that trial attorney provided ineffective assistance of counsel, the court remanded for retrial or sentencing on the remaining counts.