This particular topic always amuses me. Not in a funny-ha-ha way.
Hebrews says she was recognized for her faith. It doesn't mention her lying.
The Ten Commadments say "thou shalt not lie"; and Proverbs 6 says there are things God hates--one of them being a lying tongue.
We can argue this til the cows come home; get into deep discussions about context and "types of lying"; and look at word definitions until we're all blind.
But here's my concern: if you ask a muslim something about his brother, he's allowed to lie to you, because you're not family. If you ask about his neighbor, he's allowed to lie because you're not part of his neighborhood or village. If you ask about someone in the next village over, he's allowed to lie because you're not part of their tribe. And if you ask about someone from a different tribe or even another country, he's allowed to lie because you're not muslim.
And even though Hebrews says she was justified because of her faith, here we sit, justifying Rahab because she lied.
What's good for the muslims must be good enough for us, eh?