A wording has:

"She gave birth to a child after forty nights of her husband's death."

وَفِي لَفْظٍ: { أَنَّهَا وَضَعَتْ بَعْدَ وَفَاةِ زَوْجِهَا بِأَرْبَعِينَ لَيْلَةً [1]‏ } .‏