CLAIM: Paul refers to “Jannes and Jambres” who “opposed Moses” (2 Tim. 3:8). However, the OT never refers to either of these men. Who were they?
RESPONSE: While these two men are not recorded in the OT, they are mentioned in the Targum of Jonathan and Pliny’s Natural History (AD 77). According to the Targum of Jonathan (an Aramaic paraphrase), these two men were thought to be magicians in Pharaoh’s court in Exodus 7:11. Here, Paul is comparing their rejection of Moses with how the current false teacher’s “oppose the truth” (2 Tim. 3:8). While these two figures were not mentioned in the OT, NT authors are permitted to quote extra-biblical sources under the inspiration of the Holy Spirit (for additional comments on this subject, see Jude 9).
 Earle, R. 1 Timothy. In F. E. Gaebelein (Ed.), The Expositor’s Bible Commentary, Volume 11: Ephesians through Philemon (F. E. Gaebelein, Ed.) Grand Rapids, MI: Zondervan Publishing House. 1981. 407-408.