Abarim Publications' online Biblical Hebrew Dictionary
There are two roots of the form שמן (smn) used in the Bible, of vastly differing meanings; one denotes a growing fat and the other one has to do with the number eight. Although numerological nonsense should always be avoided, Biblical authors should also be expected to be aware and possibly make playful use of the similarity between this verb meaning to grow fat and the number eight. Note that the Hebrew word for number seven is שׁבע (shib'a), and the verb שׂבע (sb') means to be sated or saturated. The number eight could then perhaps sometimes be utilized to demonstrate excess; over-saturation, or the period beyond a fixed cycle of growth of seven temporal units (such as days or years).
The verb שמן (shaman I) means to grow fat. It only occurs a mere four times and is only employed to serve as metaphor: for arrogance (Deuteronomy 32:15, Jeremiah 5:28), complacency (Nehemiah 9:25) or dullness of heart (Isaiah 6:10). Its derivatives are:
- The adjective שמן (shamen), meaning fat or rich; of food (Genesis 49:20, Isaiah 30:23), or land (Numbers 13:20, Nehemiah 9:25). It's also used to describe the stoutness of men (Judges 3:29).
- The masculine noun שמן (shaman), describing only the fatness of the land (Genesis 27:28 and 27:39 only).
- The masculine noun שמן (shemen), sometimes meaning fatness in the same sense as the previous words (Psalm 109:24, Isaiah 5:1), but mostly denoting olive oil (שמן זית, shemen zayit). As such this word occurs 190 times in the Bible. Olive oil expressed wealth (a land of olive oil and honey; Deuteronomy 8:8), and Isaiah and Nehemiah even speak of oil-trees (Isaiah 41:19, Nehemiah 8:15). Olive oil was an ingredient of the holy anointing oil (Exodus 30:25), and was sometimes used to anoint kings (1 Samuel 10:1, 1 Kings 1:39; which brings it close to the verb משח (mashah), meaning to anoint). Olive oil could be used in a libation offering (Genesis 28:18, Isaiah 57:9), with medicinal purposes (Isaiah 1:6), to express happiness (Ecclesiastes 9:8), or for maintenance of weaponry (2 Samuel 1:21).
- The masculine plural noun אשמנים ('ashmannim), meaning the stout (= stout men; Isaiah 59:10 only).
- The masculine noun משמן (mishman), also denoting stout or vigorous ones (Psalm 78:31, Isaiah 10:16).
- The masculine noun משמן (mashman), denoting a fat portion (Nehemiah 8:10).
The root שמן (shmn II) has to do with the cardinal number eight. It isn't used as verb in the Bible (if we maintain the assumption that the following cluster of words come from an unused second root and not from the previous one), but its derivatives are:
- The masculine or feminine noun שמנה (shemoneh) or (shemonah), meaning eight (Genesis 22:23, Judges 3:8, 1 Kings 7:10).
- The adjective שמני (shemini) or שמנית (sheminit), meaning eighth (Exodus 22:29, Leviticus 25:22). This word is also the musical term Sheminith (1 Chronicles 15:21, Psalm 6:1 and 12:1).
- The plural noun שמנים (shemonim), meaning an eighty (Psalm 90:10, Jeremiah 41:5).