Hebrews 6:17-18 (NKJV)
Thus God, determining to show more abundantly to the heirs of promise the immutability of His counsel, confirmed it by an oath, that by two immutable things, in which it is impossible for God to lie, we might have strong consolation, who have fled for refuge to lay hold of the hope set before us.
Ezekiel 14:7-11 (NKJV)
"For anyone of the house of Israel, or of the strangers who dwell in Israel, who separates himself from Me and sets up his idols in his heart and puts before him what causes him to stumble into iniquity, then comes to a prophet to inquire of him concerning Me, I the LORD will answer him by Myself. I will set My face against that man and make him a sign and a proverb, and I will cut him off from the midst of My people. Then you shall know that I am the LORD. And if the prophet is induced to speak anything, I the LORD have induced that prophet, and I will stretch out My hand against him and destroy him from among My people Israel. And they shall bear their iniquity; the punishment of the prophet shall be the same as the punishment of the one who inquired, that the house of Israel may no longer stray from Me, nor be profaned anymore with all their transgressions, but that they may be My people and I may be their God," says the Lord GOD.
If I have understood the question correctly, since it does not specify exactly what the contradiction is, my guess is that the following is the "contradiction" that is seen here:
1. The passage in Hebrews claims that it is impossible for God to lie.
2. The passage in Ezekiel states that God may choose to cause a false prophet to lie.
I think when we look at what is really being claimed here, we can clearly see that there is no contradiction.
It is, I think, painfully evident that causing someone to do something is not identical to doing it yourself.
For example, a man may take his dog out on a leash. That man may travel very quickly, causing his dog to run. That same man may be in an automated wheelchair. In this example we see the following:
1. It is impossible for the man to run.
2. The man chooses to cause his dog to run.
This is the same type of scenario as the one in the scriptures in question, and it is again painfully evident that there is no contradiction here.
If the "millions" of contradictions you see in the Bible are all of this nature, we must conclude that there are no contradictions in it at all.
Before pointing out another "contradiction", I'd highly recommend that you sit down with pen and paper and write out what is being claimed in the first passage, then below it write out the exact same thing preceded by "it is not the case that" and see if your second statement really reflects what is taught in your second passage.
For example, if you had used this method before asking the above question, here is what you would have written:
1. It is impossible for God to lie.
2. It is not the case that it is impossible for God to lie.
Then you would have looked at the second statement above and compared it with the passage in Ezekiel to see if this is what Ezekiel clearly teaches. You would then have seen that this is not in fact what Ezekiel is teaching.
Thanks for the opportunity to point this out.