Suetonius
A fragment of Cassius Dio Book 78 set c. 213 CE
Historically these two passages have been connected to so called Spintriae and used to justify their false identification as brothel tokens. This is nonsense if often repeated. For a quick open access overview of the numismatic stuff see Rowan’s 2015 blog post or better yet buy her book.
I think a better reading of these passages is on the historical topos of the Despot who cares overmuch about his own portraiture as a proxy of himself and/or his power/ancestry and uses it as an excuse to inflict meaningless cruelty.
Liv Mariah Yarrow 