The Messenger of God’s sayings were a manifestation of such kind of ethics which he made known as the purpose of his mission.
In this sense, man can be needless of many types of knowledge; yet, he cannot consider himself needless of ethics since this knowledge is the capital asset of felicities in both worlds:
The purpose and result of the summons of the Seal of the Prophets (PBUH) is the perfection of morality. In the noble traditions, both that are brief and those which are elaborate, moral excellences have been given more importance than anything else after doctrinal teachings [ma‘ārif]… And their importance is greater than what we are capable of explaining adequately, but that which we know for certain is that the asset of the everlasting life of the hereafter and the capital asset of the life of that abode is the acquisition of noble dispositions and the possession of moral excellences.