en_tn/luk/21/32.md

this generation

Possible meanings are 1) the generation that will see the first of the signs Jesus spoke of or 2) the generation Jesus was speaking to. The first is more likely.

Heaven and earth will pass away

"Heaven and earth will cease to exist." The word "heaven" here refers to the sky and the universe beyond it.

my words will never pass away

"my words will never cease to exist" or "my words will never fail." This can also be translated as "my words will certainly be fulfilled" or "what I say will surely happen."