hold fast to something
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.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
hold ˈfast to somethingrefuse 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.
Farlex Partner Idioms Dictionary © Farlex 2017