Glory not over the branches (mē katakauchō tōn kladōn). Genitive case after kata. Present middle imperative second person singular of katakauchaomai with negative mē, “stop glorying” or “do not have the habit of glorying over the branches.” The conclusion of the preceding condition.
Gloriest (katakauchāsai). Late form ̇aesai retaining s.
Not thou (ou su). Very emphatic position. The graft was upon the stock and root, though each affected the other.