وَالنِّفَاسُ: هُوَ الدَّمُ الْخَارِجُ عَقِبَ الْوِلَادَةِ.
Meaning: Nifas is bleeding discharged following childbirth.
The phrase “following childbirth” is fundamental. Bleeding during pregnancy or before the baby emerges is not nifas merely because the woman is pregnant.