It's from the BDSS Volume 1; I found a site that said it meant "Whose hand is this?" but I'd like to know more if anyone can help.
Boy, am I glad I found this because trying to find out otherwise is impossible!Men Idak di, doesn't mean whose hand is this.
It's an Arabic expression, meaning I'm at your service, or under your mercy. Basically it means, whatever you tell me to do; I will do it. The literal meaning is, I'm between your hands (palms?)
The song basically says the same thing all through the lyrics. If you want me to do the lyrics for you, I will. No problem