Turban
The "turban" — rendered "turban" or "turbans" in the UPDV — is a head covering worn in ordinary life and conspicuous in mourning customs because it is precisely the item a mourner would normally remove. The umbrella draws on a single prophetic sign-act in Ezekiel, where the prophet is told to keep his turban on at the death of his wife as a sign for the exiled people.
The turban kept on in mourning
When Ezekiel is told that his wife, "the desire of [his] eyes," will be taken from him, he is forbidden the customary mourning behavior. The instructions are precise: "Sigh, but not aloud, make no mourning for the dead; bind your turban on you, and put your sandals on your feet, and don't cover your lips, and don't eat the bread of men" (Ezek 24:17).
Binding the turban — rather than uncovering the head, as bereavement would normally require — is the visible part of the sign. Sandals stay on, the lip is not covered, mourners' food is not eaten. Each detail inverts a known sign of grief.
The sign applied to the people
The meaning is unfolded later in the same chapter. What Ezekiel does becomes a model for what the exiles will do when news reaches them of the destruction of the sanctuary and the loss of their families: "And your⁺ turbans will be on your⁺ heads, and your⁺ sandals on your⁺ feet: you⁺ will not mourn nor weep; but you⁺ will pine away in your⁺ iniquities, and moan one toward another" (Ezek 24:23).
The plural-you signals that the description is for the whole audience. Their turbans will stay bound on their heads, just as the prophet's did. The expected outward acts of mourning will be withheld; an inward wasting will take their place.
What the umbrella holds
A single garment, in a single sign-act, used twice. In one verse the turban is bound on the prophet as he refuses to mourn his wife. In the other, the turbans of his hearers will likewise stay on as they refuse to mourn the catastrophes that come on Jerusalem. The umbrella collects no other use of the item — only this matched pair, the personal performance and the corporate fulfillment.