Tradition
1 Corinthians 11:2
Now I praise you, brethren, that in all things you are mindful of me: and keep my ordinances as I have delivered them to you.
Context of the passage
Before correcting Corinthian abuses regarding head coverings and the Eucharist, Paul praises them for keeping the traditions he handed on.
Catholic reading
The Greek 'paradoseis' (traditions/ordinances) shows apostolic teaching was handed down as authoritative practice independent of a completed New Testament canon, which did not yet exist.
Common objection
These 'ordinances' were merely temporary cultural customs, not doctrine.
Response
Paul uses the same word 'paradosis' for handing on the Gospel itself and the Eucharistic institution (1 Cor 15:3, 11:23), showing the term covers core doctrine, not just customs, confirming a living apostolic tradition alongside Scripture.