The verb ομνυμι (omnimu), also spelled ομνυω (omnuo), means to swear (an oath: ορκος, horkos, see below), and swearing is a peculiar thing. Swearing was invented when people discovered that language could be used for various degrees of seriousness, and even for blatant lying. Our verb ομνυμι (omnimu) stems from the Proto-Indo-European root "hemh-", which means either to swear or it means to passionately grab hold of and pull toward oneself (hence, possibly, the Latin derivative amare, from whence the familiar amor, love).

With swearing, one would marry oneself to one's statement, and so formally and solemnly vow to the fidelity of it. All that drama would not be necessary, of course, if one were widely known to never utter a falsehood, which is probably why Jesus urged to not swear and let one's yes be yes and one's no be no (Matthew 5:33-37, also see James 5:12). Alternatively (as the fictional Mark Zuckerberg character submitted in The Social Network, 2010), if one would speak the truth only when accompanied by vows and oaths, one could just as easily succumb to lying under one's oaths. One is a liar always or never, but not sometimes (and that solves the ancient riddle of the liar who confessed to lying: such a man is like dry water and cannot exist; said otherwise, a liar who tells the truth is still a liar, and his truth exists only relative to his earlier lies, which makes even his truth a lie).

The crucial failure of humans swearing, however, comes not from their intent to lie but their inevitable incomplete knowledge and power. No human always possesses all relevant knowledge, and no human controls any situation wholly (or at all, actually). That means that not even a person's most grandiose swearings perfectly guarantee the validity of that person's reports of past events or fortellings of future ones. You never know what you don't know, and you never know what might happen next. Only God does, which is why only God can swear (Luke 1:73, Acts 2:30, 7:17, Hebrews 3:11, 3:18, 4:3, 6:13, 7:21).

When God swears, he indicates that he won't change his mind, which he does, at times (Genesis 6:6, Exodus 32:14, Jeremiah 26:19, Amos 7:3). This difficult concept indicates that God, though omniscient, reacts to reality as it develops, and that quantum mechanics indeed is correct in stating that speed and position of a particle cannot be known simultaneously, not even by an omnipotent being, because these qualities do not exist as discrete entities, not even to God (who, per his own nature, doesn't bother with things that aren't real or true). When God swears, he indicates that what he swears about is governed by natural law, and natural law never changes or allows exceptions (Matthew 5:18).

Our verb is used 27 times; see full concordance, and from it come:

The noun ορκος (horkos) means an oath, or some vow sealed by means of one. The idea behind an oath is to serve as a solemn patch over a hole caused by some lack of evidence or collateral or otherwise incomplete means to convince some benefactor of the fidelity of the beneficiary. We've known since Kurt Gödel that any formal system must remain incomplete (this is fittingly called the Incompleteness Theorem of Kurt Gödel), which means that trust in any system or model must always have a keystone made out of faith.

Faith is the oath that makes all evidence complete. But since a very solemn promise is much easier made than kept, most oaths in antiquity were little more than invocations of greater powers that were called upon to avenge a reneger: "May the Great Such 'n Such do so-and-so if I don't pay back my loan next fall" (Hebrews 6:16). Unfortunately, the Great Such 'n Such often appeared to not exist, or else refused to be summoned by some oath-swearer, and many a scammer got away with his schemes.

When Jesus spoke of sowing a new patch on an old garment (Matthew 9:16) he used imagery related to faith and oaths, and illustrated the dubiosity of the whole oathing business. Instead, he urged to not swear (ομνυω, omnuo; see above) any oaths at all, by anything, but let a yes mean yes and a no mean no.

Our noun ορκος (horkos), oath, is closely akin to the noun ερκος (herkos), meaning fence or enclosure. This word isn't used in the New Testament, but it does bring to mind the similarity between the words χωρος (choros), meaning cordoned off piece of land, and χορος (choros), choir, and χαρις (charis), joy. Likewise, the verb κλειω (kleio), means to shut in or enclose, whereas the closely similar verb κλεω (kleo), means to celebrate or glorify.

Both nouns ορκος (horkos) and ερκος (herkos) stem from the Proto-Indo-European root "serk-", to fence, to recompense or make good. From that same root comes the Latin sarcio, to mend or patch, or make amends, recompense.

The Hebrew word for swearing an oath is the verb שבע (shaba'). This verb comes from the noun שבע (sheba'), meaning seven. Hence the name Elizabeth may mean God Of Oath and God Of Seven (which isn't that curious since God created everything in seven days, and has seven spirits before his throne: Revelation 1:4).

The noun ορκος (horkos), oath, is used 10 times in the New Testament, see full concordance, and from it derive (in addition to the noun ορκωμοσια, horkomosia, listed above):