(Classical Japanese) A question about 舎人が寝たる足を狐に食はる from the Tsurezuregusa

Question

The meaning of this sentence is quite clear: the feet of the sleeping servant (舎人) were eaten by a fox. However, there are two things I don't understand (you can reply to just one of them if you don't know the answer to the other):

• Why is を employed in place of の／が (or nothing at all)? I mean, 足 is the subject of the sentence, not the object, since it's a passive construction.
• I find the construction 舎人が寝たる足 very awkward... after all, it's not the feet who are sleeping. Wouldn't it be better for it to be 寝たる舎人の／が足？

Answer 1

Either bullet you listed is actually a frequent asked question in the Japanese grammar, that has its name:

• indirect passive (adversative passive) e.g. in How to interpret indirect passives?
• gapless relative (external relative) e.g. in Relative clauses distinguishing whom/with which/that

The original sentence is in the Classical Japanese, but you can create a word-for-word translation to the modern grammar to make perfect sense.

守衛が寝ている足を狐に噛まれる
A janitor have his(?) foot bitten by a fox while sleeping.

The so-called "indirect passive" reflects the different origin of Japanese passive than English. Fortunately as in the linked post, a great portion of instances in the form AがBをCにVられる can be easily transformed into English using A have B V-en by C or have C V B on A. Note that English is also equipped with special constructions for this situation.

For the "gapless relative", you can see good examples of several types in the link above too, but in general, Japanese allows you to extract any prop which is "naturally" entailed by the scene a clause describes, as a head noun to the clause. Most people, whether sleeping or not, are expected to have feet, so that 寝ている足 sounds natural and you might translate it like "the foot when (they are) sleeping" or so.