Church of St. Gervais and St. Protais, Querrieu, France
The church also has a matching sculpture of St. Protasius, with a sword in the crook of his right arm and the left hand posed as if to hold some object now lost. The sword would be his attribute, as he was martyred by beheading.
Unusually, the artist has given Gervasius as attributes both the scourge with which he was martyred and a sword like his brother's, as if he too had been beheaded.
More of St. Gervasius
Sources: Wikimedia Commons for photograph, French Ministry of Culture for date, medium, location.