Eve said that God provided this son as a replacement for Abel "whom Cain slew"
... when another son is born to Adam, 
whom his mother Eve regards as a substitute for Habel, and names .... For God, 
said she, hath appointed me another seed - semen singulars (Calvin); filium, Eve
... [DOC] [TLE] Genesis 4:25 - Bible Gateway [PAR] Adam knew [Eve as] his wife again; and she gave birth to a son, and named him 
... For God, said she, hath appointed me another seed instead of Abel, whom 
Cain slew.