בְּכֶ֥סֶף וּבְזָהָ֖ב יְיַפֵּ֑הוּ בְּמַסְמְר֧וֹת וּבְמַקָּב֛וֹת יְחַזְּק֖וּם וְל֥וֹא יָפִֽיק׃
They deck it with silver and with gold, They fasten it with nails and with hammers, that it move not.
Rashi on Jeremiah
it does not bend Heb. יפיק, it does not kneel with its knees. Comp. (I Sam. 25:31) “a stumbling block (פוקה)”; (Nahum 2:11) “and tottering (ופיק) of the knees.”