She answered and sayd to her husbande: than eate you the candell: for you sware fyrste.
In the lowest depths and loftiest heights of my own soul I sware, and He heard it.
Havelok came to him and reminding him of the oath he sware to Athelwold that Goldborough should be queen, bade him yield the land.
And they sware both of them that they would fight for their master to the death.
And Jacob said, Swear to me this day; and he sware unto him; and he sold his birthright unto Jacob.
Let them that sware the oath to Tyndareus go with thee on this errand.
Lest He sware in His wrath that you shall not enter into His rest!
Then was Fulgentius right glad, and sware to him that he would do by his counsel.
Moreouer, they sware on the holie euangelists to be true and secret each to other, euen to the houre and point of death.
Of the oath Gawain sware to the King, and how he rode forth to seek the Grail.
Old English swerian "take an oath" (class VI strong verb; past tense swor, past participle sworen), from Proto-Germanic *swarjan-, (cf. Old Saxon swerian, Old Norse sverja, Danish sverge, Old Frisian swera, Middle Dutch swaren, Old High German swerien, German schwören, Gothic swaren "to swear"), from PIE root *swer- (1) "to speak, talk, say" (cf. Old Church Slavonic svara "quarrel"). Also related to the second element in answer. The secondary sense of "use bad language" (early 15c.) developed from the notion of "invoke sacred names." Swear-word is American English colloquial from 1883. Swear off "desist as with a vow" is from 1898.