In "Sonnet 146," the soul is imprisoned and under attack from the same body of which it should be the master. The two missing words at the beginning of the second line must illustrate this desperate plight; this is why "hemmed with" fits so well. In order to identify the registers into which the missing words fit, it is helpful to examine one of the key words in the poem. The last word of the second line, "Array," has multiple meanings, each of which defines a central register of "Sonnet 146." According to the Oxford English Dictionary, array can be defined as "to adorn, deck, set off" (9b), "to disfigure, dirty, befoul, defile" (10c), "to furnish (a house)" (7a), or "a display of military force" (2a). To hem is defined as "to confine or bound by an environment of any kind, to enclose, shut in, limit, restrain, imprison" (OED 3a). The soul, imprisoned and surrounded by the body, must discard the elaborate and showy facade with which the body surrounds itself in order to don the more eternally rewarding garments of the divine. "Hemmed with" clearly illustrates the position of the soul, surrounded by a body that has rebelled against its rule, while fitting neatly into the registers of architecture, clothing, and warfare, and working hand in hand with the most important words in the poem, especially "array" (2). Thus this phrase illustrates Shakespeare’s conclusion, that only through "buying terms divine" (11) can the soul attain eternal life.
The definitions of array and hem help the reader place these words in the register of architecture, which figures prominently throughout the first two stanzas. What does a building do, if not "enclose," "shut in" (OED 3a), and hem? The words "walls" (4), "within" (3,12), "mansion" (6), and "lease" (5) all reinforce the central metaphor. In lines three through six, the poet relates his body to a "fading mansion" in which the soul is held under a state of siege. Although line six is the only time that he directly states the idea of the body as a building , Shakespeare does, in line three, begin this extended metaphor: "Why dost thou pine within and suffer dearth, / Painting thy outward walls so costly gay? / Why so large cost, having so short a lease, / Dost thou upon thy fading mansion spend?" (3-6). Not only is the soul trapped by the body, but it attempts to "adorn, deck, [and] set off" (OED 9b) its "house" with material objects rather than the more divine accouterments of religion or morality; this slow starvation will ultimately kill the soul.
Clothing is one of the most important although obscure registers in the sonnet, and the word hem, often associated with clothing, is therefore a natural choice to replace the missing words. The body is guilty of "excess" (7), which can be many things, avarice, lust, and pride, of which expensive and opulent clothing can be a manifestation. Clothing is not directly mentioned in the sonnet, but the poet does inquire of the soul why it insists on "painting [its] outward walls so costly gay" (4). In this context, the word paint can refer to makeup. Just as the body conceals and confines the soul, clothing and makeup hide the true nature of the body, a prison. The most common usage for "hem" is "To turn in and sew down the edge of (a stuff)" (OED 2a); it is usually used in reference to clothing, just as "array" can be used in the same register with its definition, "to attire, dress." (OED 8a). None of the other options presented tie into this register of clothing and adornment which remains a central part of the metaphor.
Just as walls encircle a home, and clothing encloses a body, armies can surround a city or castle, besieging it and starving the inhabitants; in "Sonnet 146" Shakespeare’s metaphor has the "rebel powers" (2) of the body starving the soul of the divine, the very thing which it needs in order to cheat death and attain immortality. The powers "hem" the soul, binding, limiting, restraining and imprisoning it. When the the soul is asked "Why dost thou pine within and suffer dearth" (3) it demonstrates the fact that the soul cannot escape from "within" its restrictive body. However, they are not directly at war, were this the case, a more active verb such as rule or starve would be appropriate. As the soul is simply at the "centre" (1) of the body’s "display of military force" (OED 2a), the more passive hem works far better.
Shakespeare’s soul of "Sonnet 146" has truly been "put into a (sore) plight" (OED 10b), no longer master of the body which is its birthright, imprisoned by the body it should control, a body which neglects the divine nature of the soul, threatening its immortal being. "Hemmed with" illustrates the dire plight of the soul while fitting perfectly into the poem’s central registers and making it a solid choice for the missing words.
"Array." The Oxford English Dictionary. 2nd ed. 1989.
"Hem." The Oxford English Dictionary. 2nd ed. 1989.