SB 9.22.8
anyasyam api bharyayam
sakale dve brhadrathat
ye matra bahir utsrste
jaraya cabhisandhite
jiva jiveti kridantya
jarasandho ’bhavat sutah
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Through the womb of another wife, Brhadratha begot two halves of a son. When the mother saw those two halves she rejected them, but later a she-demon named Jara playfully joined them and said, “Come to life, come to life!” Thus the son named Jarasandha was born.