Used to specify a general statement (Ex. He may be old in body, but he will never be old in mind)
The general statement is “he may be old” but the phrase “in body” specifies exactly how he is old.
NO prepositions used
Example: “Helvetii reliquos Gallos virtute praecedunt” (latintutorial)
Translation: The Helvetians surpass the rest of the Gauls in their virtue
The ablative case of virtute indicates that the Helvetians surpass the Gauls with respect to their virtue.