Why can't you pay interest? Something to do with religion?
Yep, religious law.
Judaism maybe?
Yes, perhaps he's a rabbi. Rabbi Muhammed Zakir
Nope. Muslim. I thought you can easily guess when you see 'Muhammed' in the name. I don't know whether any person in other religion is using that name.
~~MZ~~
Okay, so let me analyze your name.
Muhammed is a man's name, so I'm going to assume you're a man. Since that is the case, you're not going to be stoned to death for breaking some religious law. Considering you're into cryptocurrencies, I'm going to assume you're fairly progressive and not overly concerned about some weird religious law.
Just pay interest like everyone else. If that's just not possible, at least offer a tip if you're not going to pay interest. Unless someone is specifically your friend (in which case you'd be better off PMing them), the lender is going to have to get something out of it. This is especially the case with your collateral, which isn't really adequate (the signature payment isn't really collateral and .03 BTC of some unknown alt isn't going to help much).