Matthew 16:27-28?  

How is it possible for those listening to Jesus in this teaching to not taste death until

His second coming?   

27  “For the Son of Man is going to come in the glory of His Father with His angels, and will then repay every man according to his deeds. 28 “Truly I say to you, there are some of those who are standing here who will not taste death until they see the Son of Man coming in His kingdom.”

Possible answer

In Matthew 16:27-28, as well as in 10:23, Jesus is making use of  “prophetic foreshortening.  He regards the entire state of exaltation, from His resurrection to his second coming, as on single unity of teaching.  In verse 27 he describes the final consummation; whereas in verse 28 it is the beginning.  Therefore some of those he is addressing in this teaching are going to be witnesses of the beginning, which is of course His resurrection.