The Forty Martyrs of Sebaste suffered in Armenia under Emperor Licinius, A.D. 320. Refusing to sacrifice to idols they were stripped of their clothes and exposed on a frozen pond. They asked God that “the forty who had entered the lists might be forty to win the crown, forty being the number consecrated by the fasts of Jesus, Moses, and Elias”. God can raise up sons to Abraham from the stone; if we do not correspond to his grace the loss will be ours alone, since God will perform by means of another that which He would otherwise have deigned to accomplish through our instrumentality. This is what happened in the case of the Forty Martyrs of Sebaste. The angels had prepared forty crowns in heaven; one of the confessors of the Faith broke down under the torments and apostatized, but his place was immediately taken by one of the executioners, who thereby merited the fortieth crown. They were much praised by St. Basil and St. Gregory of Nyssa, and were greatly venerated even in the West.
(Source: Fr. Lasance, The New Roman Missal)