Surah Al Mu'minun Tafseer

ثُمَّ جَعَلْنَاهُ نُطْفَةً

Thereafter We made him a Nutfah.

Here the pronoun refers back to humankind, as in another Ayah:

الَّذِى أَحْسَنَ كُلَّ شَىْءٍ خَلَقَهُ وَبَدَأَ خَلْقَ الاِنْسَـنِ مِن طِينٍ

ثُمَّ جَعَلَ نَسْلَهُ مِن سُلَلَةٍ مِّن مَّأءٍ مَّهِينٍ

and He began the creation of man from clay. Then He made his offspring from semen of despised water. (32:7-8)

meaning, weak, as He says:

أَلَمْ نَخْلُقكُّم مِّن مَّأءٍ مَّهِينٍ

فَجَعَلْنَـهُ فِى قَرَارٍ مَّكِينٍ

Did We not create you from a despised water, Then We placed it in a place of safety. (77:20-21)

meaning the womb, which is prepared and readily equipped for that,

فِي قَرَارٍ مَّكِينٍ

... in a safe lodging.

إِلَى قَدَرٍ مَّعْلُومٍ

فَقَدَرْنَا فَنِعْمَ الْقَـدِرُونَ

For a known period. So We did measure; and We are the Best to measure. (77:22-23)

meaning, for a known period of time, until it is established and moves from one stage to the next.

Allah says here