'Traditions' in the Bible

So then, brothers and sisters, stand firm and hold [tightly] to the traditions which you were taught, whether by word of mouth or by letter from us.

Now we command you, believers, in the name of our Lord Jesus Christ and by His authority, that you withdraw and keep away from every brother or sister who leads an undisciplined life and does not live in accordance with the tradition and teaching that you have received from us.