Dust

Boyd’s Bible Dictionary:

(storm breath). Symbol of mourning (Josh. 7:66And Joshua rent his clothes, and fell to the earth upon his face before the ark of the Lord until the eventide, he and the elders of Israel, and put dust upon their heads. (Joshua 7:6); Isa. 47:11Come down, and sit in the dust, O virgin daughter of Babylon, sit on the ground: there is no throne, O daughter of the Chaldeans: for thou shalt no more be called tender and delicate. (Isaiah 47:1)); feebleness (Gen. 18:2727And Abraham answered and said, Behold now, I have taken upon me to speak unto the Lord, which am but dust and ashes: (Genesis 18:27); Job 30:1919He hath cast me into the mire, and I am become like dust and ashes. (Job 30:19)); countless numbers (Gen. 13:1616And I will make thy seed as the dust of the earth: so that if a man can number the dust of the earth, then shall thy seed also be numbered. (Genesis 13:16)); low condition (1 Sam. 2:88He raiseth up the poor out of the dust, and lifteth up the beggar from the dunghill, to set them among princes, and to make them inherit the throne of glory: for the pillars of the earth are the Lord's, and he hath set the world upon them. (1 Samuel 2:8)); rage (2 Sam. 16:1313And as David and his men went by the way, Shimei went along on the hill's side over against him, and cursed as he went, and threw stones at him, and cast dust. (2 Samuel 16:13); Acts 22:2323And as they cried out, and cast off their clothes, and threw dust into the air, (Acts 22:23)); renunciation (Matt. 10:1414And whosoever shall not receive you, nor hear your words, when ye depart out of that house or city, shake off the dust of your feet. (Matthew 10:14); Mark 6:1111And whosoever shall not receive you, nor hear you, when ye depart thence, shake off the dust under your feet for a testimony against them. Verily I say unto you, It shall be more tolerable for Sodom and Gomorrha in the day of judgment, than for that city. (Mark 6:11); Acts 13:5151But they shook off the dust of their feet against them, and came unto Iconium. (Acts 13:51)). A sand storm (Deut. 28:2424The Lord shall make the rain of thy land powder and dust: from heaven shall it come down upon thee, until thou be destroyed. (Deuteronomy 28:24)).

Concise Bible Dictionary:

Small particles of matter found on the ground, out of which man was formed, to whom it was said, “Dust thou art, and unto dust shalt thou return” (Gen. 2:77And the Lord God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul. (Genesis 2:7); Gen. 3:1919In the sweat of thy face shalt thou eat bread, till thou return unto the ground; for out of it wast thou taken: for dust thou art, and unto dust shalt thou return. (Genesis 3:19)). “The first man is of the earth, earthy” (1 Cor. 15:4747The first man is of the earth, earthy: the second man is the Lord from heaven. (1 Corinthians 15:47)). It is used as a symbol of weakness: “he remembereth that we are dust” (Psa. 103:1414For he knoweth our frame; he remembereth that we are dust. (Psalm 103:14)). To “lick the dust” is figurative of defeat (Psa. 72:99They that dwell in the wilderness shall bow before him; and his enemies shall lick the dust. (Psalm 72:9)). To “cast dust upon the head” was a sign of grief (Ezek. 27:3030And shall cause their voice to be heard against thee, and shall cry bitterly, and shall cast up dust upon their heads, they shall wallow themselves in the ashes: (Ezekiel 27:30); Rev. 18:1919And they cast dust on their heads, and cried, weeping and wailing, saying, Alas, alas, that great city, wherein were made rich all that had ships in the sea by reason of her costliness! for in one hour is she made desolate. (Revelation 18:19)). To “shake the dust off the feet” on leaving a city where the servants of Christ had been rejected, was leaving them to judgment: not even the dust of their city should be presented before the messengers’ Master (Matt. 10:1414And whosoever shall not receive you, nor hear your words, when ye depart out of that house or city, shake off the dust of your feet. (Matthew 10:14); Acts 13:5151But they shook off the dust of their feet against them, and came unto Iconium. (Acts 13:51)). Similarly dust was cast or shaken into the air by men in great indignation (Acts 22:2323And as they cried out, and cast off their clothes, and threw dust into the air, (Acts 22:23)).

“280. Dust Throwing” From Manners and Customs of the Bible:

Throwing dust at a person is an Oriental mode of expressing anger and contempt. In addition to the instance here given we find another in the history of Paul. The mob whom he addressed in Jerusalem became very much excited at his speech and sought to destroy him, declaring that he was not fit to live, and as evidence of their fury they “threw dust into the air” (Acts 22:2323And as they cried out, and cast off their clothes, and threw dust into the air, (Acts 22:23)). The precise meaning of this symbolic action we do not know. There may, however, be some connection between this custom and the practice of persons in trouble putting dust on their own heads in token of grief. See the preceding note (#279). Throwing dust at others may be a symbolic mode of wishing them such trouble and grief that they may feel like covering themselves with dust, as an expression of their sorrow.

“523. Dust Shaken Off” From Manners and Customs of the Bible:

Jewett, in his Christian Researches, refers to the custom of Orientals sitting on the ground with their feet drawn under them, gradually gathering dust on their garments, and rising occasionally to shake it off; and then resuming their seats. This, however, is only a partial explanation of the allusions of the text. The “dust” referred to may be either that in which Jerusalem had been sitting, or that which she had put upon her head. In either case the idea of mourning would be represented. The mourner is exhorted to arise from the dust and take a higher position; not to sit down again in the dust. The language seems to embrace the idea of a throne, a high seat. Alexander agrees with some of the best expositors who adopt the interpretation of the Targum, Sit upon thy throne. From this Jerusalem is supposed to have been previously cast down. The ground was to be left, the dust shaken off, and the throne occupied. The mourning was to be changed for rejoicing.

“655. Heathen Dust” From Manners and Customs of the Bible:

The schools of the scribes taught that the dust of heathen lands was defiling. They therefore objected even to bringing plants or herbs from heathen countries, lest some of the dust should come with them. Some of the rabbins permitted this, provided no dust was brought with the plants. They give this gloss to the rule: “They take care lest, together with the herbs, something of the dust of the heathen land be brought, which defiles in the tent, and defiles the purity of the land of Israel.” See LIGHTFOOT, flora Hebraicae.
The Saviour, doubtless, alluded to this rabbinical rule, and, by using the expression of the text, conveyed the idea to his disciples that every place which should reject them was to be considered heathen, impure, profane.
When Paul and Barnabas were driven from Antioch, in Pisidia, “they shook of the dust of their feet.” See Acts 13:5151But they shook off the dust of their feet against them, and came unto Iconium. (Acts 13:51).