Josephus, Tacitus, and Eusebius wrote that they saw the return of Jesus, as Jesus stated He was returning in the clouds during the generation of the disciples, in Matthew 24, Mark 13 and Luke 21 in 66 AD.
Matthew 10:23: King James Version
23 But when they persecute you in this city, flee ye into another: for verily I say unto you, Ye shall not have gone over the cities of Israel, till the Son of man be come.
Matthew 10:23 New American Standard Bible (NASB)
23 “But whenever they persecute you in one city, flee to the next; for truly I say to you, you will not finish going through the cities of Israel until the Son of Man comes.
Jesus said: “…That there be some of them that stand here, which shall not taste of death, till they have seen the kingdom of God come with power…”
Jesus said to His disciples that He was returning in the clouds and bringing His Kingdom–inside us–during the generation of His disciples
A study of Matthew 24:1-3; 34-35: And as he sat upon the mount of Olives, the disciples came unto Him privately, saying, Tell us, when shall these things be? and what shall be the sign of Thy coming, and of the end of the world?-Richard Duke