CASH / MacCASH / MacCAISH(e) - From the "Surnames of Scotland", pg. 466: MACCASH, MACASH, MACCAISH. Perthshire surnames, probably contracted forms of MacTavish. Hector McCaishe was one of those holding the castle of Dunivaig against Bishop Know, 1616 (or 1614) (Cawdor, p. 232) (Other variant spellings on this page: M'Ash, McCaish, M'Caish, M'Cais)
From the Denmylne Mss. in the Highland Papers, pg. 203-205, the name of Hector McCaishe was spelt as Hector McCawis and Hector McCaus.
From the "Surnames of Scotland", pg. 456: MACCAVISH, MACCAUSE, MACCAVISH, MACCAWIS, MACCAWS. In Gaelic, MacThdmhais, 'son of Tammas', the Scottish form of Thomas. (Other variant spellings on this page: McCawis, M'Awis, MCause, Makavhis, Makawis, M'Caws, Makcawis, VcAlves, McAves, VcCavyes, McCaweis, McCaueis, McAvis, McAvish, Mccavish, Mcavish, M'Awishe, M'Cauish, McKawes, VcKaviss)
From the "Extracts from the Potalloch Writs", The Genealogist New Series, Edited by H. W. Forsyth Harwood, Barrister-at-Law, Volume XXXVIII, 1922, pg 138-142 - Lands of Dunardarie -- The Chiefs names are spelled as VcCaus, McCawis, McCzawis, McTavish, VcCawis.
You can see from just these three sources, the possible connection of Cash with Clan MacTavish, even so far as the Chiefly line having some of the same spellings as the Cash surname. However, again - this is not proof that your Cash family is a part of Clan MacTavish or even related to the families of the Chiefly line. You must do your own genealogical research to determine that fact, and not fall into the romance of being convinced that you are "part" of any Clan because of a surname spelling. You will find information on surnames and cautions about them by Prof. George Black in SURNAMES OF SCOTLAND in his lengthy "Introduction". Pay close attention to the words in the items you research: probably, possibly, perhaps.
Another caution is that "whatever you learn today may very well change tomorrow". New information is uncovered, etc. Be prepared to keep an open mind.
NOTE: Many of the Cash family members in the US believe we are descended from the sister (or half-sister or niece) of Malcolm IV of Scotland - Ada (Ela) married Duncan, Earl of Fife. If that is true, then this family is descended from Kenneth MacAlpin of Scotland and his Irish ancestors. Under these circumstances, Earl Downey (my father) would possibly be the 33rd cousin 3 times removed of Dugald Edward Stewart MacTavish, Chief of Clan MacTavish. Chief MacTavish states that Cash is a connected name of Clan MacTavish, deriving from M'Ash and MacCamish.
This family also believes that our name may have been MacCash in Scotland. If this is true, then the "Surnames of Scotland" by Professor George Black supports MacCash connection to MacTavish.
From Ireland, Scotland, and Sweden they came, as well as many other European countries. Mariners, farmers, physicians, politicans, clergymen, homemakers, storekeepers, soldiers and their children. People with integrity and endurance. An industrious people coming to forge a new life for their families. To Masachusetts and the southeastern seabord, migrating to Virginia, then KY>TN>NC>AR>IL>MO>KS and on to TX and UT, naming but a few of the states. From this CASH family comes shipbuilders and their families (who weathered the witchcraft trials of Salem), neighbors of the family of Abraham Lincoln, soldiers in the Revolutionary and Civil Wars, plantation owners. They gave us country entertainer, Jonny CASH, and Rev. Warren CASH who built the Giliad Baptist Church in Hardin Co., KY. Lucy Tyler (of President Tyler's family) married into the CASH family. We live in a fast-paced society, at times forgetting that we are "KIN". Let us stop for a moment and celebrate the rich heritage that we share!