Is recourse made to consensus (Ijma') when there is no evidence from the Qur'an and Sunnah? And what is the meaning of their saying: "Consensus (Ijma') supported by the Qur'an or Sunnah"?

Consensus (Ijma') is the third source of Islamic legislation after the Qur’an and Sunnah (definition). It is not an independent proof from them, but rather subservient to them. Every consensus is based on a legal text, whether known or unknown. The indication of a text might be obscure or disputed, so consensus clarifies the ruling and indicates that the text is sound and its understanding allows no other interpretation. Scholars have agreed that the Ummah does not concur on a ruling except based on a source and evidence that necessitates their agreement. Sheikh Al-Islam Ibn Taymiyyah emphasized that there is no issue upon which there is consensus except that there is a clarification from the Messenger concerning it. Consensus may be used as evidence by those who are unaware of the text’s indication. Consensus is another proof, alongside the text, indicating the truth, with both being intertwined.