Saint Ambrose

When I am at Rome I fast as the Romans do; when I am at Milan I
do not read more

When I am at Rome I fast as the Romans do; when I am at Milan I
do not fast. So likewise you, whatever church you come to,
observe the custom of the place, if you would neither give
offence to others, nor take offence from them.

When I am at Rome, I fast on a Saturday: when I am at Milan I do
not. Do read more

When I am at Rome, I fast on a Saturday: when I am at Milan I do
not. Do the same. Follow the custom of the church where you
are.

If you are at Rome live in the Roman style; if you are elsewhere
live as they live elsewhere.
read more

If you are at Rome live in the Roman style; if you are elsewhere
live as they live elsewhere.
[Lat., Si fueris Romae, Romano vivito more;
Si fueris alibi, vivito sicut ibi.]