Fred Sanders has an interesting post on Isaiah 63:17:

Why, O LORD, do You cause us to stray from Your ways
And harden our heart from fearing You?
Return for the sake of Your servants, the tribes of Your heritage.

In it, he references the perspectives of two commentators, one Calvinistic and one Wesleyan. The conclusions they draw are fairly similar in that neither one would say the author is passing the blame for their sins to God, making Him the author of their sins and making Him responsible for them.

Although not stated in the same way, we can see a similar situation in Exodus 4 when God says He will harden Pharaoh’s heart so that he will not let the Israelites leave Egypt. The difference here being Pharaoh did not believe in God and the person speaking in Isaiah 63 is an Israelite.

So, what can we glean from this passage in Isaiah? Obviously it is a great passage on the sovereignty of God and it reminds us that God is at work in all things for His name’s sake. But we can also find what the Israelites did when they were trapped in their sins; they focused on who God is. Look at verses 15-16 in that same chapter in Isaiah. The people revered God, they recalled His workings from of old and recognized Him as their redeemer. This is a great lesson for us when we are struggling with indwelling sin. Focus on the redeemer and not the redeemed.