مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2014
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
"Amr bin Deenar narrated that Abush-Sha"tha told him that Ibn "Abbas told him that he heard the Messenger of Allah (ﷺ) deliver a speech in which he said: "Whoever cannot find an izar but can find pants, let him put them on, and whoever cannot find sandals but can find leather slippers (khuffain), let him put them on.” I said: Did he not say to cut them down? He said: No.
Musnad Ahmad 2015Sahih (Darussalam) [, alBukhari (1841) and Muslim (1178)]