Tafsiran Keluaran 25:27: Rashi, Chizkuni, Or HaChaim & Rashbam

לעמת המסגרת תהיין הטבעת OVER AGAINST THE RIM SHALL THE RINGS BE — inserted in the legs over against the extremities of the border.

לעומת המסגרת תהיינה, “they (the rings) were attached to the rim at the of the table as holders for the staves, i.e. on the outer edges of the table.

לבתים לבדים, as housings for the staves. Whereas I have explained in connection with the rings of the ark that Betzalel had to cast four rings and attach them firmly to the ark, whereas he would insert a second set of rings inside the first ones to support the staves, the Torah here alters its instructions. Here there was no need to make a second set of rings. The rings mentioned here were the ones into which the staves were inserted directly.

לבתים לבדים FOR PLACES FOR THE STAVES — These rings shall be receptacles in which to put the staves.

לבתים means for the purpose of being (to serve as) receptacles for the staves, as the Targum has it: places for the staves.