hold fast to something

hold fast

1. To remain securely adhered (to something). I didn't think the makeshift weld would do the trick, but I'm happy to say that it's holding fast.
2. To remain determined, stalwart, and unyielding, as in one's position or opinion. Though it may be hard, we must hold fast in our pledge to environmental reform.
See also: fast, hold
Farlex Dictionary of Idioms.

hold ˈfast to something

refuse to stop believing in something such as a theory, principle, religion, etc: She knew that whatever happened in her life, she would hold fast to her religious beliefs.
See also: fast, hold, something
Farlex Partner Idioms Dictionary
See also:
  • hold fast
  • hold firm
  • keep in good condition
  • remain
  • remain at some place
  • all (other) things being equal
  • screw (one's) courage to the sticking place
  • screw up (one's) courage to the sticking place
  • stand by (one's) guns
  • stick by (one's) guns