Jesus personally guaranteed what he had said. My words include what Jesus said in Mark 13:1–37. Mark’s audience would have understood this as guaranteeing the truth of all the teachings of Jesus known to them (Luke 1:2).
Like the Old Testament Scriptures (see Isa 40:8), the words of Jesus are eternal. His teachings are more permanent than the basic parts of creation itself. The basic elements of creation will pass away (see also Ps 102:25–26; Isa 40:6–8; 51:6; Matt 5:18; Luke 16:17; 2 Pet 3:7, 10; Rev 20:11), but the words of Jesus will never disappear.