In the construction of a law or instrument, the office of the judge or jury, as the case may be, is simply to ascertain and declare what is in terms or in substance contained therein, not to insert what has been omitted, or to omit what has been inserted, and where there are several provisions or particulars, such a construction is, if possible, to be adopted as will affect all.

SOURCE: CCP § 1858.

COMMENT: Reference to juries is added. It is understood that construction of the law remains with the judge (§ 2118 of this Division). However, other instruments can be subject to jury interpretation.