|Easton's Bible Dictionary|
A lifting up, gift, one of the sons of Ishmael, the founder of an Arabian tribe (Genesis 25:14); a nomad tribe inhabiting the Arabian desert toward Babylonia.
Int. Standard Bible Encyclopedia
mas'-a (massa', "burden"): Descendant of Abraham through Ishmael (Genesis 25:14 1 Chronicles 1:30). His people may be the Masani of Ptolemy, having Eastern Arabia near Babylon as their habitat. The marginal reading of the heading to Proverbs 31 mentions Lemuel as king of Massa. If that reading is accepted, it would seem that a tribe and probably a place were named from Ishmael's descendant. The reading is doubtful, however, for where the phrase recurs in Proverbs 30 (Revised Version (British and American)) it appears to be a gloss.
Massa (4 Occurrences)
Genesis 25:14 Mishma, Dumah, Massa, (WEB KJV JPS ASV BBE DBY WBS YLT NAS RSV NIV)
1 Chronicles 1:30 Mishma, and Dumah, Massa, Hadad, and Tema, (WEB KJV JPS ASV BBE DBY WBS YLT NAS RSV NIV)
Proverbs 30:1 The words of Agur, the son of Jakeh, from Massa. The man says: I am full of weariness, O God, I am full of weariness; O God, I have come to an end: (BBE RSV)
Proverbs 31:1 The words of Lemuel, king of Massa: the teaching which he had from his mother. (BBE RSV)