From BiblePortal Wikipedia

Hastings' Dictionary of the Bible [1]

Arpachshad was, according to   Genesis 10:22 , the third son of Shem, and, according to   Genesis 11:10 , he was the second in the line of descent from Shem to Abraham.   Genesis 10:22 is an enumeration of peoples (or countries) descended from Shem, from which Babylonia or Chaidæa is absent in the present text. The latter portion of the word furnishes Chesed (cf.   Genesis 22:22 ), which is the singular form of Chasdim (Chaldees). Probably two words in the original of   Genesis 10:22 were combined into one, the latter being Chesed and the former Arpach , which is a region south-west of Assyria, possibly the same as the Arrapachitis of Ptolemy. The mistaken reading in   Genesis 10:22 was then taken as the basis of   Genesis 11:10 ff.

J. F. McCurdy.

Holman Bible Dictionary [2]

 Genesis 10:22 Luke 3:36 Genesis 10:1