´Abu Bakr bin An-Nadr said:` "We were in At-Taff with Anas, and he led them in praying Zuhr. When he had finished, he said: 'I prayed Zuhr with the Messenger of Allah (ﷺ) and he recited two surahs for us in the two rak'ahs: "Glorify the Name of your Lord, the Most High' and 'Has there come to you the narration of the over-whelming (i.e. The Day of Resurrection)?'"
Explanation & Benefits
Hafiz Muhammad Ameen
973. Commentary: Both of the aforementioned narrations are weak in terms of their chain of transmission. However, the Imam may recite an ayah or some words aloud even in silent (sirrī) prayers so that the followers (muqtadis) can gauge the recitation and know how much time remains before bowing (ruku‘), and thus they may complete their own recitation on time, as is supported by other evidences. However, this audible recitation should be less and distinct from the recitation in audible (jahrī) prayers so that the distinction remains clear. Evidently, this audible recitation was done by you (the Prophet sallallahu alayhi wa sallam) intentionally. But it is also possible that sometimes the voice became loud unintentionally.
Source: Sunan Nasa'i: Translation and Benefits by Shaykh Hafiz Muhammad Amin Hafizullah, Page: 973