談空說有

From Su Shi's poem 《寄吳德仁兼簡陳季常》 ("Poem sent for Wu Deren and for Chen Jichang as well") (translation from Qiu, 2013^[1]):

• 龍丘居士亦可憐，
  談空說有夜不眠，
  忽聞河東獅子吼，
  柱杖落手心茫然。 [Literary Chinese, trad.]

  ---

  龙丘居士亦可怜，
  谈空说有夜不眠，
  忽闻河东狮子吼，
  柱杖落手心茫然。 [Literary Chinese, simp.]

  Lóngqiū jūshì yì kělián,
  Tán kōng shuō yǒu yè bùmián,
  Hū wén hédōng shīzǐ hǒu,
  Zhù zhàng luò shǒu xīn mángrán. [Pinyin]

  The lay practitioner of Dragon Hill is also pitiful,
  he stays up discoursing on emptiness and fullness all night long.
  Suddenly he hears a lion’s roar from east-of-the river,
  the cane drops from his hand, he is at a loss.

Originally meaning "to discuss non-existence and existence → to discuss Buddhist doctrines", it then underwent semantic pejoration to "gossip, idle talk, empty talk".

談空說有

1. gossip, idle talk, empty talk