Actually, the main culprit may be not the sodium it's self in the ramen noodles but the MSG. I swell up like a balloon if I eat something with MSG in it...9+lbs wouldn't be a surprise. Give it a few days, it should go back down, but you may want to kind of keep track of foods with MSG and weight fluctuations. It may help pinpoint what's causing so much water retention (unless of course, you did in fact eat 31,000+ calories over the weekend, which I'm sure you'd remember
)
It's painful to see such a significant gain in one weekend, but you can be sure you did not gain 9+lbs of fat. Just keep moving forward.