In these sentences, Imam ‘Ali (as) emphasizes two ethical principles:
1. Do not talk on anything you lack information about. This is because your statements might turn out to be false. In such cases you have both told a lie and misled people into ignorance, both of which are religiously forbidden. Such a case would lower one’s social position.
2. Do not interfere in anything not related to you and so do not speak of anything not concerning you. The Prophet (S) has said: "Among a Muslim’s good deeds is to leave anything that does not concern him."2
1. Sharh Nahj al-Balaghah by Ibn Abi’l Hadid, vol.16, pp.63-64; and by Ibn Maytham, vol.5, p.10.
2. Op cit.