Berean Standard Bible (BSB)
Therefore, brothers, stand firm and cling to the traditions we taught you, whether by speech or by letter.
World English Bible (WEB)
So then, brothers, stand firm, and hold the traditions which you were taught by us, whether by word, or by letter.
Strong's King James
Therefore{G686}{G3767}, brethren{G80}, stand fast{G4739}{(G5720)}, and{G2532} hold{G2902}{(G5720)} the traditions{G3862} which{G3739} ye have been taught{G1321}{(G5681)}, whether{G1535} by{G1223} word{G3056}, or{G1535}{G1223} our{G2257} epistle{G1992}.
The F.O.G *
(15) So then indeed brothers, stand firmly and hold to the traditions you were taught, whether through word or a letter of us.
The F.O.G Message *
Young's Literal Translation
so, then, brethren, stand ye fast, and hold the deliverances that ye were taught, whether through word, whether through our letter;