'Sackcloth' in the Bible

Now it will come to pass that instead of the sweet fragrance of spices there will be [the stench of] rottenness;Instead of a belt, a rope;Instead of well-set hair, baldness;Instead of fine clothes, a robe of sackcloth;And branding [of captives by the scorching heat] instead of beauty.

In their streets they have wrapped themselves with sackcloth;On their [flat] housetops and in their open squaresEveryone is wailing, dissolved in tears.

at that time the Lord spoke through Isaiah the son of Amoz, saying, “Go, untie the sackcloth from your hips and take your sandals off your feet.” And he did so, walking around stripped [to his loincloth] and barefoot.

Therefore in that day the Lord God of hosts called you to weeping, to mourning,To shaving the head and to wearing sackcloth [in humiliation].

Tremble, you women who are carefree;Tremble with fear, you complacent ones!Strip, undress and wear sackcloth on your waist [in grief],

And when King Hezekiah heard this, he tore his clothes and covered himself with sackcloth and went into the house of the Lord.

Then he sent Eliakim, who was in charge of the [royal] household, and Shebna the scribe, and the elders of the priests, covered with sackcloth, to Isaiah the prophet, the son of Amoz.

“I clothe the heavens with the blackness [of storm clouds]And make sackcloth [of mourning] their clothing.”

“Is a fast such as this what I have chosen, a day for a man to humble himself [with sorrow in his soul]?Is it only to bow down his head like a reedAnd to make sackcloth and ashes as a bed [pretending to have a repentant heart]?Do you call this a fast and a day pleasing to the Lord?