'Dust and Ashes' in the Bible

And Abraham answered and said, Behold now, I have taken upon me to speak unto the Lord, which am but dust and ashes:

Jehovah giveth the rain of thy land -- dust and ashes; from the heavens it cometh down on thee till thou art destroyed.

He hath cast me into the mire, and I am become like dust and ashes.

Wherefore I abhor myself, and repent in dust and ashes.

Weep not, lest they at Gath perceive it. Thou at Bethleaphrah, welter thyself in the dust and ashes.