This Bible contradiction is from the Skeptic's Annotated Bible.

Verses

As a sign that he would heal Hezekiah's boil

2 Kings 20:7-11 View context

And Isaiah said, Take a lump of figs. And they took and laid [it] on the boil, and he recovered.

And Hezekiah said unto Isaiah, What [shall be] the sign that the LORD will heal me, and that I shall go up into the house of the LORD the third day?

And Isaiah said, This sign shalt thou have of the LORD, that the LORD will do the thing that he hath spoken: shall the shadow go forward ten degrees, or go back ten degrees?

And Hezekiah answered, It is a light thing for the shadow to go down ten degrees: nay, but let the shadow return backward ten degrees.

And Isaiah the prophet cried unto the LORD: and he brought the shadow ten degrees backward, by which it had gone down in the dial of Ahaz.

As a sign that he would defend the city against the Assyrians

Isaiah 38:4 View context

Then came the word of the LORD to Isaiah, saying,