The poet draws an analogy between an old clock and a monk in these lines from a poem. Which phrase is analogous to "its case of massive oak"?

Halfway up the stairs it stands,

And points and beckons with its hands

From its case of massive oak,

Like a monk, who, under his cloak,

Crosses himself, and sighs, alas!

With sorrowful voice to all who pass,—

(from "The Old Clock on the Stairs" by Henry Wadsworth Longfellow)

sorrowful voice

its hands

crosses himself

his cloak