פירוש על שבת 46:2

Two spouts: As their lamps were of clay. And they were covered, so they made a hole on the sides of the cover to insert a wick into it, and that is the spout. And above, in the cover, there is [another] small hole; and there is also an empty space above the cover and he fills it with oil, and it enters through the [small] hole, little by little. If it has two holes from two sides, it counts for two people as beautified (mehadrin) - those that do a lamp for each person.

Made it like a bonfire: As the fire connects in its center and it is not similar to a lamp [any more].