I overheard in a Sunday school lesson that the etymology of the word "righteous" includes the concept of a covenant that has since been lost in translation. However, I have been unable to find anything that indicates a direct etymological relationship between these.
From etymonline I have found:
righteous (adj.) an early 16c. alteration of the older word, rightwise, which is from Old English rihtwis, of actions, "characterized by justice, morally right," of persons, "just, upright; sinless, conforming to divine law," from riht (see right (adj.1)) + wis "wise, way, manner" (see wise (adj.)). The alteration of the ending is by influence of courteous, etc. As a noun, "those who are righteous," Old English rehtwisan. The meaning "genuine, excellent" is 1942 in jazz slang. Related: Righteously.
Upright gets force from the idea of physical perpendicularity, a standing up straight by the standard of right ; righteous carries up the idea of right to the standards, motives, and sanctions of religion ; rightful applies not to conduct, but to claims by right : as, he is the rightful owner of the land ; just suggests by derivation a written law, but presumes that the law is a right one, or that there is above it, and if necessary overruling it, a law of God. This last is the uniform Biblical usage. Just generally implies the exercise of some power or authority. [Century Dictionary]
From Strong's Concordance I was able to find
Strong's Concordance tsadeq or tsadoq: to be just or righteous Original Word: צָדַק Part of Speech: Verb Transliteration: tsadeq or tsadoq Phonetic Spelling: (tsaw-dak') Definition: to be just or righteous NAS Exhaustive Concordance Word Origin denominative verb from tsedeq Definition to be just or righteous
And from the NASB Exhaustive Concordance I was able to find:
NASB Translation acquit (1), acquitted (1), declare you right (1), do justice (1), give him justice (1), just (2), justified (5), justifies (1), justify (5), justifying (2), lead the to righteousness (1), made your appear righteous (2), properly restored (1), proved right (1), proved...righteous (1), right (4), righteous (9), vindicated (1), vindicates (1).
Obviously, there is a multitude of scriptures that connect righteousness with the keeping of covenants, but the statement that was given says there is an actual etymological connection between the word righteous and the word covenant. If anyone knows what that is, could you please supply me with an explanation or reference?