Mark 13:30

13:30 I tell you the truth, ¹  this generation ²  will not pass away until all these things take place.

Mark 16:12

16:12 After this he appeared in a different form to two of them while they were on their way to the country.

Mark 16:17

16:17 These signs will accompany those who believe: In my name they will drive out demons; they will speak in new languages; ³ 

[13:30]  ¹ tn Grk “Truly (ἀμήν, amhn), I say to you.”

[13:30]  ² sn This is one of the hardest verses in the gospels to interpret. Various views exist for what generation means. (1) Some take it as meaning “race” and thus as an assurance that the Jewish race (nation) will not pass away. But it is very questionable that the Greek term γενεά (genea) can have this meaning. Two other options are possible. (2) Generation might mean “this type of generation” and refer to the generation of wicked humanity. Then the point is that humanity will not perish, because God will redeem it. Or (3) generation may refer to “the generation that sees the signs of the end” (v. 26), who will also see the end itself. In other words, once the movement to the return of Christ starts, all the events connected with it happen very quickly, in rapid succession.

[16:17]  ³ tn Grk “tongues,” though the word is used figuratively (perhaps as a metonymy of cause for effect). To “speak in tongues” meant to “speak in a foreign language,” though one that was new to the one speaking it and therefore due to supernatural causes. For a discussion concerning whether such was a human language, heavenly language, or merely ecstatic utterance, see BDAG 201-2 s.v. γλῶσσα 2, 3; BDAG 399 s.v. ἕτερος 2; L&N 33.2-4; ExSyn 698; C. M. Robeck Jr., “Tongues,” DPL, 939-43.