What is the ruling on speaking about a matter without sufficient knowledge of it, or without remembering its details well, or without knowledge?

A Muslim must seek truthfulness and trustworthiness in his speech, and his words must be beneficial. He must avoid speaking based on conjecture or on what he has no knowledge of, because Allah Almighty says: (O you who have believed, fear Allah and be with the truthful) [Surat At-Tawbah (definition): 119], and because the Prophet, peace and blessings be upon him, said: "Hold fast to truthfulness, for truthfulness leads to righteousness, and righteousness leads to Paradise." Allah has forbidden conjecture, saying: (O you who have believed, avoid much [negative] assumption. Indeed, some assumption is sin) [Surat Al-Hujurat: 12], and speaking without knowledge: (And do not pursue that of which you have no knowledge) [Surat Al-Isra: 36]. The prohibition of speaking without knowledge is emphasized in matters of Islamic law, because the Prophet, peace and blessings be upon him, said: "Whatever you know from it, act upon it, and whatever you are ignorant of, refer it back to its scholar."