tam and tamim

Two similar adjectives appear throughout the Bible: tam (תָּם) and tamim (תָּמִים). Both come from the root תמ"ם, and both can describe someone as upright, complete, or perfect. But they aren't always used in exactly the same way. Yaakov (Bereshit 25:27) is called an אִישׁ תָּם, while Noach (Bereshit 6:9) is an אִישׁ צַדִּיק תָּמִים. Iyov (Iyov 1:1) is תָּם וְיָשָׁר, while Avraham (Bereshit 17:1) is commanded to be תָמִים. So what is the difference between the two words?Let's start with the root תמ"ם. The Ben-Yehuda Dictionary gives the basic meaning of the verb תמם as "to be complete, finished." We find that meaning in verses such as וַיִּתְּמוּ יְמֵי בְכִי אֵבֶל מֹשֶׁה, "the days of mourning for Moshe came to an end" (Devarim 34:8). That basic idea of completion or wholeness is the starting point for both adjectives.The words tam and tamim are two different adjective forms built from the same root. The ending of tamim may look like a masculine plural ending, but tamim itself is…