It is generally accepted that when a bill (for example) is introduced in one house of Congress, it must be approved by both houses before that Congress adjourns. A bill approved by one house cannot be carried over for approval by the other house across congressional terms. The Constitution does not overtly mandate this (unless the mandate is very subtle).
Is there an "official" mechanism encoding this result? For example a statute passed into law at some point; rules of the House and Senate that declare this; or some SCOTUS ruling that mandates this as a result of the common law? Or is this just one of those "it's how we've always done it" things?