Tafsir of Ad-Dhariyat 51:49

ومن كل شيء خلقنا زوجين

And of everything We have created pairs, meaning, all the created are in pairs, the heaven and earth, night and day, sun and moon, land and sea, light and darkness, faith and disbelief, death and life, misery and happiness, Paradise and Fire, in addition to the animals and plants. The statement of Allah the Exalted,

لعلكم تذكرون

that you may remember. (and know that the Creator, Allah, is One without partners),