יָתֵד הִיא שֶׁלֹּא תִּימּוֹט

ביטוי (אנגלית)

A peg that shall not be moved

הגדרה (אנגלית)

Figuratively: the matter is stable and there is no chance that it will collapse. Stable and secure.

("And at times you did not say to us thus (Did you not sometimes not say to us like this)?" He said to her: "It is a peg that shall not be moved" - Gittin 17a)