This is a good place to start:

We have all become like one who is unclean, and all our righteous deeds are like a polluted garment. We all fade like a leaf, and our iniquities, like the wind, take us away. --Isaiah 64:6

Btw, the Hebrew for "polluted garment" is more literally "menstrual rag".

But I think there is a lot of misunderstanding about total depravity. The Heidelberg Catechism has this to say about what it means to do something good:

Q91. What do we do that is good?

A. Only that which arises out of true faith, conforms to God's law, and is done for his glory; and not that which is based on what we think is right or on established human tradition.

And who would argue that natural man can do anything that fits that definition apart from grace? Here is the Canon of Dordt on the topic of total depravity:

Therefore all men are conceived in sin, and by nature children of wrath, incapable of saving good, prone to evil, dead in sin, and in bondage thereto, and without the regenerating grace of the Holy Spirit, they are neither able nor willing to return to God, to reform the depravity of their nature, nor to dispose themselves to reformation.

If you simply delete the word "regenerating" from that article, you get something that both John Wesley and Thomas Aquinas could agree to (because of prevenient grace).

Understood this way, total depravity is not a "Calvinist" doctrine but one affirmed by the whole western church (the Eastern Orthodox have a distinctly different understanding of original sin). It only becomes Calvinist-specific when you start arguing over prevenient vs. regenerating grace, which to me seems like a pretty minor issue.

This is a good place to start:

We have all become like one who is unclean, and all our righteous deeds are like a polluted garment. We all fade like a leaf, and our iniquities, like the wind, take us away. -- Isaiah 64:6, ESV

Btw, the Hebrew for "polluted garment" is more literally "menstrual rag".

But I think there is a lot of misunderstanding about total depravity. The Heidelberg Catechism has this to say about what it means to do something good:

Q91. What do we do that is good?

A. Only that which arises out of true faith, conforms to God's law, and is done for his glory; and not that which is based on what we think is right or on established human tradition.

And who would argue that natural man can do anything that fits that definition apart from grace? Here is the Canon of Dordt on the topic of total depravity:

Therefore all men are conceived in sin, and by nature children of wrath, incapable of saving good, prone to evil, dead in sin, and in bondage thereto, and without the regenerating grace of the Holy Spirit, they are neither able nor willing to return to God, to reform the depravity of their nature, nor to dispose themselves to reformation.

If you simply delete the word "regenerating" from that article, you get something that both John Wesley and Thomas Aquinas could agree to (because of prevenient grace).

Understood this way, total depravity is not a "Calvinist" doctrine but one affirmed by the whole western church (the Eastern Orthodox have a distinctly different understanding of original sin). It only becomes Calvinist-specific when you start arguing over prevenient vs. regenerating grace, which to me seems like a pretty minor issue.