The Talmud answers: The Rabbis hold that only the married daughter of a priest who committed adultery is singled out from all those who commit adultery, for burning, but not one who is betrothed, as a betrothed woman who committed adultery, whether or not she is the daughter of a priest, is executed by stoning. And since God singles out a betrothed woman who is not married from all married women who commit adultery, to be executed by stoning, conclude from it that stoning is more severe than burning.
סקילה חמורה מסייף, שכן ניתנה למגדף ולעובד עבודה זרה. ומאי חומרא? כדאמרן.
Stoning is considered more severe than decapitation by the sword, as it is meted out to one who blasphemes and to one who worships idols. And for what reason is the severity of these transgressions considered greater than others? As we said, it is because the transgressors undermine the fundamental tenets of Judaism.
אדרבה: סייף חמור, שכן ניתן לאנשי עיר הנדחת. ומאי חומרא? שכן ממונן אבד.
The Talmud raises an objection: On the contrary; decapitation by the sword would appear to be more severe than stoning, as it is meted out to the people of an idolatrous city, who also undermine the fundamental tenets of Judaism. And for what reason is the severity of this case of an idolatrous city considered greater than others? Because the transgressors are not only executed, their property is destroyed as well.
אמרת: איזה כח מרובה, כח המדיח או כח הנידח? הוי אומר: כח המדיח. ותניא: מדיחי עיר הנדחת – בסקילה.
The Talmud answers: In response to this objection, you should say: The severity of which transgression is greater: The severity of the transgression of the one who subverts the city, inciting them to sin, or the severity of the transgression of the subverted? You must say that the severity of the transgression of the subverter is greater. And it is taught in a baraita: The subverters of an idolatrous city are executed by stoning. Evidently, stoning is a more severe type of execution than decapitation.