From the bay that looketh southward - These were the southern limits of the tribe of Judah, which commenced at the extremity of the lake Asphaltites or Dead Sea, and terminated at Sihor or the river of Egypt, and Mediterranean Sea; though some think it extended to the Nile.

And their south border was from the shore of the salt sea, from the (a) bay that looketh southward:
(a) The Hebrew word signifies tongue, by which it means either the arm of the sea that comes into the land, or a rock, or cape that goes into the sea.

And their south border was from the shore of the salt sea,.... Sometimes called the dead sea, the sea of Sodom, and the lake Asphaltites, which, as Jarchi observes, was southeast of the land of Israel:
from the bay that looketh southward; or the "tongue", as the Hebrew, which the Targum and Kimchi interpret of a rock or promontory, the point that ran out into the sea, looking to the southeast.

the bay--Hebrew, "tongue." It pushes its waters out in this form to a great distance [ROBINSON].

The bay - Hebrews. the tongue: either a creek or arm of that sea; or a promontory, which by learned authors is sometimes called a tongue. Every sea is salt, but this had an extraordinary saltness, the effect of that fire and brimstone which destroyed Sodom and Gomorrah: the ruins of which lie buried at the bottom of this dead water, which never was moved itself by any tides, nor had any living thing in it.