I am rather new to the site, so I don't know if there is already a canon "beginning" to the Foundation, but based on some SCP articles I have read, it seems to go bak quite a while. Therefore I began to ponder what the Foundation would be in ancient times (i.e. Biblical) and found some interesting correlations between the Foundation and the Biblical Israelite Society. My Old Testament is not perfect, so I might be erroneous.
1) Society was broken into three groups: Israelites, Levites, and Cohen. The Israelites (General Populous) do not interact with the workings of the other groups, the Levites (Agents) retrieve, transport, and maintain many of the artifacts, as well as deal with the people, and the Cohen (Researchers) look over the artifacts. This fits in with the hidden Foundation in society.
2) Special, deadly items are mentioned, and they have special containment procedures. For example, an ark that only the high priest is allowed to see, an unexplained ritual which done wrong caused the death of Aaron's two sons and forced him to clean himself, and a disease that affects people, clothing, and buildings alike.
3) Also, the miracles that followed them around could be seen as SCP's such as manna, the rain of quail, rods that brought forth water, and an everlasting pillar of smoke and fire.