Frost's poem contains one of the most quoted lines in all of poetry; "Home is the place where, when you go there, they have to take you in" (lines 118-119).
The idea is that "home" is the one place where you cannot be rejected. One is bonded for life to their biological ties, but "home" is also the place where love creates an unbreakable bond.
The conflict of the concept of home occurs when the itinerant worker, Silas, makes himself too comfortable, in the eyes of Warren, the owner of the home he shares with his wife, Mary. Warren feels that Silas is taking advantage of them and their good nature, making claims of "home" to which he has no right, for Silas is not a blood relation.
Mary, however, is more open to the concept of home. She feels that because Silas has placed such trust in them, and because Silas has no other place to go, that the man can rightfully claim their home as refuge, even if he has a living relative. Mary pleads with her husband, "But have some pity on Silas. Do you think / If he had any pride in claiming kin/ Or anything he looked for from his brother, / He'd keep so still about him all this time?" (135-38). For additional leverage, Mary reminds Warren of Silas' service. "But Warren," she cajoles, "please remember how it is: / He's come to help you ditch the meadow" (156-57).
Home, indeed, is where the heart is.