Reference for Zevachim 122:7
ר"נ בר יצחק אמר מאי לא נסתלקה לא נסתלקה לבטלה מאי היא רבנן אמרי שביבא הוה משדרא רב פפא אמר אושפיזא הוה נקט וזימנין הכא וזימנין הכא
For it was taught, R'Nathan said: The altar at Shiloh was of brass; it was hollow, and filled with stones.<span class="x" onmousemove="('comment',' The answer is not clear. Presumably it means that it was Moses' brazen altar except that the hollow was filled with stones instead of earth.');"><sup>14</sup></span> R'Nahman B'Isaac said: What does 'it did not depart' mean? It did not depart [disappear] into nothingness.<span class="x" onmousemove="('comment',' Lit., 'in vain,' 'for no purpose.' Until Solomon built the Temple the fire did not completely depart from Moses' altar which was still in existence, for though it did move to the altar at Shiloh, some of it nevertheless remained on that of Moses.');"><sup>15</sup></span>