In DP Verse 25, we read about Arhat Culapanthaka displaying psychic powers (appearing as many) to possibly a lay person, i.e. the messenger:
When the messenger from the house of Jivaka arrived at the monastery he found not only one bhikkhu, but a thousand identical bhikkhus.
Now it's popularly known that according to the Vinaya, Bhikkhu are prohibited from displaying psychic powers to lay persons (Kevatta Sutta DN 11). If so, was this display by Arhat Culapanthaka,
- before the vinaya prohibiting such displays,
- performed unaware of such a rule,
- exempt from the rule,
- not exempt from the rule, but the intention and effect due to the display of such powers, was of greater benefit than non display.