Shaykh Ḥammād al-Anṣārī said, 

If a person were to analyse Sūrah al-ʿAṣr, he would increase in certainty that the Qur’ān is the Speech of Allāh, the Most High. This is because there is no one (besides Him) capable of summarising all of virtue in three verses. Imām ash-Shāfiʿī said, “If the people were to contemplate this chapter, it would suffice them.” Sūrah al-ʿAṣr is an explanation of the whole Qur’ān.