Formal:
* Tenez bon à cela: This translates directly to "Hold fast to that." It is a formal way to express that someone should maintain their position or decision.
* Restez ferme sur cette position: This means "Stay firm on this position," implying that someone should not change their mind.
Informal:
* Tiens bon sur ça: This is a more casual way to say "Hold on to that."
* Ne lâche pas: This translates to "Don't let go," and implies that someone should stick to their plan or idea.
* Persévère: This means "Persevere," encouraging someone to keep going despite difficulties.
The best translation will depend on the specific situation and the level of formality you want to convey.