New Defender's Study Bible Notes
16 great swelling words. False teachers are often characterized by grandiose speech, designed to flatter and ingratiate themselves with their audience. The same phrase is used in II Peter 2:18.
17 the apostles. Here Jude assumes that he himself is not one of the apostles of Christ, but he refers to their teachings as of divine authority.
18 mockers in the last time. This is almost a verbatim quotation from II Peter 3:3. Jude quotes this as he would the Scriptures, indicating that very soon after Peter wrote his last epistle (the canonicity of which has long been rejected by false teachers, even more emphatically than most other books of the New Testament), it was known and accepted by the early church as of divine authority. This verse, incidentally, confirms that Jude understood that his epistle in all its urgency would be especially relevant to “the last time.”