Mbh 13.4.3c

I had so ordered that thou wouldst give birth to a Brahmana whose virtues would be famous throughout the three worlds, and that she (thy mother) would give birth to an excellent Kshatriya. But now, O excellent lady, that thou hast reversed the order (of the charu) so, thy mother will give birth to an excellent Brahmana and thou too, O excellent lady, will give birth to a Kshatriya terrible in action. Thou hast not done will, O lady, by acting thus out of affection for thy mother.'--Hearing this, O king the excellent lady Satyavati, struck with sorrow, fell upon the ground like a beautiful creeper cut in twain. Regaining her senses and bowing unto her lord with head (bent), the daughter of Gadhi said to her husband, that foremost one of Bhrigu's race,--'O regenerate Rishi, O thou that art foremost amongst those versed in Brahma, do thou take pity on me, thy wife, who is thus appeasing thee and so order that a Kshatriya son may not be born unto me. Let my grandson be such a one as will be famous for his terrible achievements, if it be thy desire, but not my son, O Brahmana. Do thou confer this favour on me.'--'Be it so,'--said that man of austere penances to his wife and then, O king, she gave birth to a blessed son named Jamadagni. The celebrated wife of Gadhi too gave birth to the regenerate Rishi Viswamitra versed in the knowledge of Brahma, by favour of that Rishi. The highly devout Viswamitra, though a Kshatriya, attained to the state of a Brahmana and became the founder of a race of Brahmanas. His sons became high-souled progenitors of many races of Brahmanas who were devoted to austere penances, learned in the Vedas, and founders of many clans.