﴿ فَٱتَّخَذَتْ مِن دُونِهِمْ حِجَابًۭا فَأَرْسَلْنَآ إِلَيْهَا رُوحَنَا فَتَمَثَّلَ لَهَا بَشَرًۭا سَوِيًّۭا ﴾

“and kept herself in seclusion from them, whereupon We sent unto her Our angel of revelation, who appeared to her in the shape of a well-made human being.”

Please check ayah 19:21 for complete tafsir.