The Unbreakable Knot

You touch a length of cord, rope, chain or similar item and it will tie a knot around an object or become bound around a creatures hands and feet no larger than large size; and you must have enough material components to actually tie that creature. If the creature is not willing and is conscious, it must make a Strength or Dexterity Saving Throw, being bound by the spell on a failure. You and any creatures you designate when you cast this spell can untie the knot normally. You can also set a password that, when spoken within 5 feet of the object, suppresses this spell for 1 minute. Otherwise, it is impassable until it is broken or the spell is dispelled or suppressed. Casting the Knock spell on the bindings suppresses this spell for 10 minutes and will allow the binding to be removed; after 10 minutes the bindings will reattach itself. The spell when cast will only bind the object or the person it was original cast on until broken. The bindings can be broken by making a Athletics check against your Spell Save DC.