From BiblePortal Wikipedia

Hastings' Dictionary of the Bible [1]

SABTECA . The youngest son of Cush according to   Genesis 10:7 . The only identification at all plausible has been made with Samydake on the E. side of the Persian Gulf. But this is improbable, since that region did not come within the Cushite domain, as judged by the names of the other sons of Cush. Possibly Sabteca is a miswriting for Sabtah (wh. see).

J. F. McCurdy.

International Standard Bible Encyclopedia [2]

sab´tḗ - ka ( סתּכא , ṣabhtekhā'  ; Σαβακαθά , Sabakathá , Σεβεθαχά , Sebethachá  ; the King James Version Sabtechah ): The 5th named of the sons of Cush in the genealogy of   Genesis 10:5-7 . In  1 Chronicles 1:8 ,  1 Chronicles 1:9 the King James Version reads "Sabtecha," the Revised Version (British and American) "Sabteca." Many conjectures have been made as to the place here indicated. Recently Glazer ( Skizze , II, 252) has revived the suggestion of Bochart that it is to be identified with Samydake in Carmania on the East of the Persian Gulf. This seems to rest on nothing more than superficial resemblance of the names; but the phonetic changes involved are difficult. Others have thought of various places in Arabia, toward the Persian Gulf; but the data necessary for any satisfactory decision are not now available.