[Pooya/Ali Commentary 70:40] Allah calls to witness His own power and glory manifested in the splendour of sunrise and sunset at different points through the solar year. Refer to the commentary of Saffat : 5; Waqi-ah: 75 and Haqqah: 38 and 39. By scepticism and obstinate negation of rational arguments and signs visible in the working of creation the disbelievers not only do not find any sense of direction in their individual and social life in this world but also shall be certain losers in the hereafter.