from Late Latin mammona, from Greek mamonas, from Aramaic mamona, mamon "riches, gain." This word was left untranslated in the Greek New Testament (e.g. Matt. vi:24, Luke xvi:9-13) and was retained in the Latin Vulgate; thereafter it was mistakenly thought by medieval Christians to be the name of a demon.
"No servant can serve two masters: for either he will hate the one, and love the other; or else he will hold to the one, and despise the other. Ye cannot serve God and mammon [money]." - Luke 16:13
"In an irrefutable, axiomatic way, we can and even must define mammon with two terms: