"Indeed, We created man from a drop [of fluid]" means: the descendants of Adam. "Amshaj (mingled)" is interpreted by al-Hasan as: the man's fluid mingled with the woman's fluid.
﴿إِنَّا خَلَقْنَا الإِنْسَانَ مِنْ نُطْفَةٍ﴾ يَعْنِي: نسل آدم ﴿أمشاج﴾ تَفْسِيرُ الْحَسَنِ: يَعْنِي: مَشَجَ مَاءُ الرَّجُلِ بِمَاءِ الْمَرْأَةِ.