the mahabharata tells about her marriage. sage jagatkāru decided to abstain of marriage. he came across a group of men who were hanging upside down from a tree. these men were his ancestor who were doomed because their children did not perform their last rites. so they asked jagatkāru to marry and to have a son who can perform the rites to free them. vasuki offered jagatkāru his sister, manasa. although jagatkāru was abstaining from marriage he accepted. manasa gave birth to their son, astīka. astīka performed the rites and freed their ancestor. astīka also helped nāga from a yanja, a fire offering by stopping the king janamejaya.