Imam Ali (AS) said, If you are ignorant then learn, and when you are asked about that which you do not know then say: Allah and His Prophet know better.
الإمامُ عليٌّ (عَلَيهِ الّسَلامُ) : إذا كُنْتَ جاهِلاً فَتَعَلَّمْ وَ إذا سُئِلْتَ عَمّا لا تَعْلَمْ فَقُلْ: اَللّهُ وَ رَسُولُهُ أعْلَمُ
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Mishkāt al-Anwār #721Ameer al-Momineen (a.s) said: “Whoever says God and the Prophet knows best when asked about something which he does not know is a pious...