What is the difference between a Sahih Hadith and a Hadith whose Isnad is Sahih?

The Hadith scholars determine that an authentic (sahih) hadith is one that fulfills five conditions: the uprightness of its narrators, their precision, the continuity of its chain of transmission (isnad), and freedom from anomalousness (shudhudh) and defectiveness (illah). The last two conditions are subtle and difficult to ascertain, which is why many later scholars contented themselves with verifying the first three conditions by saying: "a sound isnad," to distinguish it from "a sound hadith," which encompasses all five conditions. This is because the isnad might be sound while the text (matn) is anomalous or defective. However, an exception might be made if it is known that a trusted Imam, especially among the early scholars, does not differentiate between the two terms in his terminology. In such a case, his intent by saying "a sound isnad" would be to authenticate the hadith itself with all its conditions.