Surah Maryam 19:9

قَالَ كَذَٰلِكَ قَالَ رَبُّكَ هُوَ عَلَىَّ هَيِّنٌ وَقَدْ خَلَقْتُكَ مِن قَبْلُ وَلَمْ تَكُ شَيْـًٔا

[An angel] said, "Thus [it will be]; your Lord says, 'It is easy for Me, for I created you before, while you were nothing.'"

Translation: Saheeh International

Tafsir

He said ‘It the matter in question of creating a boy from both of you shall be so! Your Lord says “It is easy for Me namely to restore your sexual potency and tear open your wife’s womb in preparation for conception for I certainly created you before when you were nothing”’ you were nothing before your created form …

Excerpt from Tafsir al-Jalalayn, commentary on 19:9, via Quran.com. The reader has the full commentary and 9 more tafsirs.