Why will they build a battlement of silver and close her with boards of cedar?

They answer their own question about what to do with her. Their sister is both a wall and a door. The wall speaks of fortification and impregnability, indeed virginity; their task is to ornament as well as to strengthen this wall with battlements of silver, increasing both its impregnability and its beauty and thus its value to a potential suitor.

The door is a bit different. It both denies entrance, but also grants it to some. We have already seen how she has opened the door to her husband (Song of Solomon 7:13). To her brothers, the woman as door means they must enclose her with boards of cedar, which lays the emphasis now on defense rather than beautification.

They see their task, in other words, both as ensuring that men stay away from their sister until the proper time and as making sure that she is a prize catch when that time comes. They see themselves as the ones who decide when that proper time might be.¹

Her purity is unblemished, and the brothers propose to adorn that feature as their marketing strategy. The mention of silver reminds us that the brother’s motivations are far from personally disinterested: silver points back to Song of Solomon 8:7 and on to Song of Solomon 8:11 as the medium of commercialized love. The high wall, with its fortifications of silver, is aimed at keeping the girl in as much as it is at keeping unwelcome suitors out.²

The imagery here serves to describe how the brothers view their sister. An immature young woman who does not know what is best. They see her as someone that not only needs their protection, but as a valuable commodity that they can benefit from. It may seem strange that they are speaking of her in this way at this stage of the Song, when we as the reader have already heard about her love affair with the young man that has blossomed into the consummation of their marriage. But the view that the brothers have of their sister is introduced here to serve as a contrast to how she views herself and indeed how her husband views her.