Albert Barnes Commentary 1 Kings 17:16

"The jar of meal wasted not, neither did the cruse of oil fail, according to the word of Jehovah, which he spake by Elijah." — 1 Kings 17:16 (ASV)

This is the first recorded miracle of its kind—a supernatural and inexplicable multiplication of food (compare to 2 Kings 4:42–44, Matthew 14:15–21, and Matthew 15:32-38).

The sacred record does not explain these miracles. But if the explanation sometimes suggested is true—that there was a transformation of previously existing matter into meal, oil, fish, and bread—then the marvel itself is not much greater than the astonishing natural chemistry in plant growth. Through this process, particles of water, air, and earth are transformed into fruits and grain, and so made suitable for human food.

There would be a difference in the agency involved and in the time taken for the transformation, but the resulting act would be almost the same.