Error referencing static members in query

[sflanker]

public static class QueryableFilterThing {
    private static Int32 MagicNumber { get; } = 42;

    public static Answer AnswerUltimateQuestion(this IQueryable<Answer> allAnswers) {
        return allAnswers.Where(a => a.Id == MagicNumber).Single();
    }
}

This function raises an error indicating that the MagicNumber member is not supported. The same query works if a local variable is used instead.