(Addariyath) 51 : 49
وَمِنْ كُلِّ شَيْءٍ خَلَقْنَا زَوْجَيْنِ لَعَلَّكُمْ تَذَكَّرُونَ
And from everything We have created in pairs, so that they may be remembering.
See explanation 32: 4; 35: 27-29; and 36: 36.