دَآئِبَيۡنِۖboth constantly pursuing their coursesdāibayni
وَسَخَّرَand subjectedwasakhara
لَكُمُfor youlakumu
ٱلَّيۡلَthe nightal-layla
وَٱلنَّهَارَand the daywal-nahāra
Tafsir
Allah subjugated the sun and the moon to continuously orbit. He subjugated the day and the night to alternate, the night for your sleep and rest and the day for your activity and work.