In al-Talkhis, it is described as authentic according to Muslim’s criteria. Al-Hafiz said in al-Fath (10/79):

“Its chain is strong.”

401 — “When you stand for prayer, pray as one bidding farewell; do not speak words for which you will have to apologize tomorrow; and give up all hope of what people possess.”

Ibn Majah (2/542), Ahmad (5/412), and Abu Nu'aym in al-Hilyah (1/462) narrated it from Abdullah ibn Uthman ibn Khuthaym ibn Uthman ibn Jubayr, the freedman of Abu Ayyub, from Abu Ayyub al-Ansari, who said: A man came to the Prophet, peace and blessings be upon him, and said, “Give me admonition, but be concise.” He then gave him this counsel.

This is a weak chain of transmission, because Uthman ibn Jubayr is unknown. Al-Mizan states: “As far as is known, no one narrated from him other than Abdullah ibn Uthman ibn Khuthaym.” Al-Taqrib states: “Maqbul (acceptable).” The rest of the narrators are trustworthy.

Al-Zawa'id states: “Its chain is weak. Al-Dhahabi said in al-Tabaqat that Uthman ibn Jubayr is unknown.” Ibn Hibban listed him among the trustworthy narrators, while al-Bukhari and Abu Hatim said: “He narrated from his father, from his grandfather, from Abu Ayyub.”

After citing these remarks from al-Zawa'id, the annotator al-Sindi, may Allah have mercy on him, said: “Yet the fact that this hadith is among the most concise and comprehensive statements of wisdom indicates that it is close”