What's left out can say a lot.

Reading Room in Library of Congress

Nor should the eunuch say,“See, I am a dry tree.”For thus says the LORD:To the eunuchs who keep my sabbaths,who choose what pleases me,and who hold fast to my covenant,I will give them, in my houseand within my walls, a monument and a nameBetter than sons and daughters;an eternal name, which shall not be cut off, will I give them.  Isaiah 56:3b-5

These verses from the opening poem of Third Isaiah are not include in the lectionary reading for today.  The lines that are included speak to the universality of the re-establishment of Israel after the Babylonian Captivity.  The old laws about exclusivity and restriction to a chosen race are now to be understood differently.  Who your ancestors were is no longer the central issue.  Faithfulness to the covenant and "keeping the sabbath" now become the operative principles.  While earlier passages in first Isaiah indicate that Yahweh's promise of faithfulness is unconditional, Third Isaiah introduces a different note:  the obligation of the Divine One's people to live a righteous life in response to the Divine One's faithful relationship to them.

Now, in Third Isaiah, Yahweh's people clearly includes foreigners who can join the "chosen people" on an equal footing.  " For my house shall be called a house of prayer for all peoples."  But what about people who are "damaged goods," who are disfigured and imperfect physically?  What about the eunuchs?  Torah excluded such people from Temple worship participation because their physical imperfection was in conflict with the ritual purity laws.  In an ideal sense, this did not have any implication for their inherent worth as human beings but clearly over time such would be the inevitable result.  Third Isaiah says that even these people can enter into the family of the Divine One on an equal footing.

Why the lectionary excludes these verses is anybody's guess.  Mine would be a fear that somehow homosexuality would be understood as normal and acceptable.  Whether these lines can legitimately be understood in that way is a question that others would have to answer.  The more important point is the nature of this "equal footing."

Frederick Gaiser has helped me understand the fundamental point of the passage:

Finally, in the eyes of the prophet, it is not a matter of eunuchs and foreigners being "allowed" into a community that is whole in itself and that now condescends to let in some who, alas, are not like them. Rather, God is gathering "others" to "the outcasts of Israel" that God has "already gathered" (56:8). The people of Israel can accept the inclusion of others because they know themselves to be outcasts and sinners, welcome in God’s house because of who God is and what God has done, not because of their own righteousness. There is no "we" who magnanimously admit "them"; there is a community of outcasts who together recognize their common need of undeserved grace.  http://www.religion-online.org/showarticle.asp?title=3404

Indeed, there is no "we" and no "them."  We are a community of outcasts who are enlivened by undeserved grace.  How sad that this understanding is weakened by ecclesiastical "powers that be" who feel the need to "protect" "us" from "them."