You probably rinsed & dried your hands after washing them, so there was probably just trace amounts of soap on them when you briefly put them in the tank. Do a water change daily for the next few days, now is the time to run carbon in the filter.
Honestly, I wouldn't worry too much about it. I work in a shop all day with ink & solvents, it takes some serious soap to get this half way out of your hands. The only way it comes out completely is with a weeks vacation. I don't think twice about putting my hands in any of my tanks after work, and have never had a problem.
If you dropped a bottle of soap in there, it's time for a total tear down & cleaning. Hand cream & lotions are bad because you don't rinse them off. Many people wash, rinse, & dry their hands before putting them in tanks, just so they don't contaminate the tank with some foreign substance. The only other option is never washing your hands.
Animals are more resilient than you may think, aquatics equipment & supplies are not manufactured in hospital sterile environments. I can guarantee there are solvents & chemicals involved in manufacturing plastic filter cases & parts, and they don't run aquarium gravel through a scrubbing & sterelization process.
Tolak