不入虎穴，焉得虎子。

Nothing ventured, nothing gained.

One may only catch the tiger cub by entering the tiger's den.

Source: Tatoeba

Sentence Composition

1 不 bù
  1. no; not so
  2. (bound form) not; un-
2 入 rù
  1. to enter; to go into
  2. to join; to become a member of
  3. (bound form) to conform to (as in 入时 rùshí)
  4. abbr. for 入声 rùshēng
  5. (on product packaging, after {number n} + {classifier}) containing (n pieces) (from Japanese 入 "iri")
3 虎穴 hǔxué
  1. (figurative) danger spot; dangerous place
  2. danger spot; dangerous place
  3. tiger's den
4 焉 yān
  1. where
  2. how
=5 得 dé
  1. to obtain
  2. to get
  3. to gain
  4. to catch (a disease)
  5. proper
  6. suitable
  7. proud
  8. contented
  9. to allow
  10. to permit
  11. ready
  12. finished
=5 得 dè used in 得瑟 dèse
=5 得 de structural particle: used after a verb (or adjective as main verb), linking it to following phrase indicating effect, degree, possibility etc
=5 得 děi
  1. to have to
  2. must
  3. ought to
  4. to need to
6 虎子 hǔzǐ
  1. tiger cub
  2. brave young man