Hi. Thanks for your query. Noted the history of a knot that has come up on the arch of foot which has reduced, 1/2 to 3/4 left behind, the knot is approximately 2 long X 1.5 wide, no pain, knot feels tight, and is kind of hard, not stepped on anything that would have caused this. Since the knot is big bu asymptomatic, the most probable cause can be cornification for some foreign body that might have passed innocuously in past and the cornification occurred now without any pain or so. Another possibility can be an insect bite, this is possible as some insect bites are painless and yet cause severe local reaction without any pain. I would advise you to consult your Doctor, preferably a General Surgeon so that a proper diagnosis can be made and further medical or surgical management done as per the cause confirmed. Til then, so not apply anything to the lesion nor do any massage, do not try to cut through at home.