How we cite our quotes: (Book.Chapter.Bekker #s); all Bekker line numbers are approximate, since they are keyed to the original Greek.
Quote #10
The just peculiar to a slave master and to a father are not the same as these [political senses] of justice, though they are similar. For there is no injustice in an unqualified sense toward one's own things, but one's property or offspring...is like a part of oneself, and nobody chooses to harm himself. (5.6.1134b9-12)
Aristotle's declaration regarding both slaves and offspring (and one can add wife to this list) highlights the very narrow application of the concept of justice in this work. While justice as a general concept doesn't encompass these relationships, Aristotle believes that there's a more natural sense of justice that should regulate virtuous behavior toward these marginalized human beings.
Of course, without the application of general or particular justice in these cases, it means that the law won't legislate concerning them—which means that there's no sense that these people can ever be wronged (and so: no justice if they are).
Quote #11
This is in fact the nature of the equitable: a correction of law in the respect in which it is deficient because of its being general. For this is the cause also fo the fact that all things are not in accord with law: it is impossible to set down a law in some matters, so that one must have recourse to a specific decree instead. (5.10.1137b27-29)
Aristotle understands that the law isn't perfect in its interpretation of what's just or unjust and lays the blame for that at the feet of non-specificity. Because lawgivers can't always legislate for every specific case that might come before them, there's bound to be a moment when the law fails to do what is right.
This is where the concept of equity comes in. Note that "equity" is not the same as "equality": while equality ensures that people have the proper proportion of the good, equity is the principle that perfects justice. It's the back door that allows an equitable person to make corrections to the law to restore the balance of society in specific cases.