Jyut talk:00168

《易經》ji6 ging1 is jik6 ging1

The character 易 has two separate meanings, each with its own pronunciation:

  jik6 change, as in The Book of Changes (here)
  ji6 easy, as in 容易 'easy'

Mandarin lost its syllable-final stops, leaving the two pronunciations identical. This is at least the 3rd appearance of this problem.