[aljarry]

It's also New Testament, but the "Riches" is capitalized in specific translation you're using, it's not capitalized in New King James, and neither in New International Version. I'd wager it's relatively modern addition.

To see if that point is actually in the sources, you would need to go into Greek, or look for a good historic analysis of Gospel of Matthews.

[edit]

Ten commandments come from oral tradition, but most probably were written down at least a few hundreds years earlier (500 or 600BC)