Sunan an-Nasa'i, 400

It was narrated that Abu Hurairah said:"None of you should urinate into standing water which does not flow and then perform Ghusl with it." (One of the narrators) Sufyan said: "They said to Hisham - meaning Ibn Hassan - 'Ayyub only attributed this Hadith to Abu Hurairah?' So he said: 'If Ayyub is not able to raise up a narration then he does not raise it.'" [1] [1] That is, he narrated it from Abu Hurairah, rather than from him from the Prophet (ﷺ) while others narrated it in Marfu' form or "raised" to the Prophet (ﷺ) And perhaps by: "If he is able to not raise it" he means: "If he is not able to raise it." And Allah knows best

Rapporté par Abu Hurairah : Aucun de vous ne doit uriner dans de l’eau stagnante qui ne coule pas, puis faire le ghusl avec. (Un des transmetteurs), Sufyan, a dit : « Ils ont demandé à Hisham – c’est-à-dire Ibn Hassan – “Ayyub a-t-il seulement attribué ce hadith à Abu Hurairah ?” Il a répondu : “Si Ayyub ne peut pas remonter une narration, alors il ne la remonte pas.” »