Didache

Let every Apostle who comes to you be received as the Lord,

but let him not stay more than one day, or if need be a second as well; but if he stay three days, he is a false prophet.

And when an Apostle goes forth let him accept nothing but bread till he reach his night’s lodging; but if he ask for money, he is a false prophet.

Do not test or examine any prophet who is speaking[*](Prophets) in a spirit, for every sin shall be forgiven, but this sin shall not be forgiven.

But not everyone who speaks in a spirit is a prophet, except he have the behaviour of the Lord. From his behaviour, then, the false prophet and the true prophet shall be known.

And no prophet who orders a meal in a spirit shall eat of it: otherwise he is a false prophet.

And every prophet who teaches the truth, if he do not what he teaches, is a false prophet.