Mass. R. Evid. 602
A witness may testify to a matter only if evidence is introduced sufficient to support a finding that the witness has personal knowledge of the matter. Evidence to prove personal knowledge may consist of the witness's own testimony. This section does not apply to a witness's expert opinion testimony under Section 703.
Mass. Guid. Evid. 602
This section is taken from Fed. R. Evid. 602 and Proposed Mass. R. Evid. 602 and is consistent with Massachusetts law. See Commonwealth v. Cintron, 435 Mass. 509, 521 (2001); Malchanoff v. Truehart, 354 Mass. 118, 121-122 (1968); Commonwealth v. Wolcott, 28 Mass. App. Ct. 200, 207 (1990).
The personal-knowledge requirement also applies to hearsay declarants. See, e.g., Commonwealth v. Drapaniotis, 89 Mass. App. Ct. 267, 274-276 (2016) (reversing conviction of firearm offense, based on insufficiency of evidence, where sole evidence on element of gun's operability was gun owner's testimony of hearsay statement by salesman, admitted without objection but not supported by any indication of salesman's personal knowledge).
Section 104(b), Preliminary Questions: Relevance That Depends on a Fact; Section 601, Competency; Section 703, Bases of Opinion Testimony by Experts. Cf. Section 402, General Admissibility of Relevant Evidence; Section 403, Excluding Relevant Evidence for Prejudice, Confusion, Waste of Time, or Other Reasons; Section 701, Opinion Testimony by Lay Witnesses.