Jabir bin Samura reported,

The people of Kufa complained about Saad to Umar , so he removed him from his post and appointed Ammar over them. They continued to complain, even claiming that he did not know how to pray properly. So Umar sent for him and said, "Abu Ishaq, these people claim that you do not know how to pray well."Abu Ishaq replied, "By Allah, I used to lead them in prayer just as the Messenger of Allah ﷺ prayed, without falling short of it in any way. I would lead them in the Isha prayer, lengthening the first two rakahs and shortening the last two."Umar said, "That is what I thought of you, Abu Ishaq."Then Umar sent a man, or some men, with him to Kufa to inquire about him among its people. He left no mosque without asking about him, and the people praised him favorably, until he entered a mosque belonging to Banu Abs. A man among them named Usama bin Qatada, known as Abu Sadah, stood up and said, "Since you have asked us under oath, I will say that Saad did not march with the army, did not distribute the spoils equitably, and was not just in his judgments."Saad said, "By Allah, I will make three supplications. O Allah, if this servant of Yours is a liar and rose to speak out of show and to be heard, prolong his life, prolong his poverty, and expose him to trials."Afterward, whenever the man was asked about himself, he would say, "I am an old man afflicted with trials. The supplication of Saad has struck me."Abdul-Malik said, "I saw him later, his eyebrows drooping over his eyes from old age, accosting young girls in the streets and pinching them."

حدثنا موسى قال حدثنا أبو عوانة قال حدثنا عبد الملك بن عمير

عن جابر بن سمرة قال

شكا أهل الكوفة سعدا إلى عمر رضي الله عنه فعزله واستعمل عليهم عمارا فشكوا حتى ذكروا أنه لا يحسن يصلي فأرسل إليه فقال يا أبا إسحاق إن هؤلاء يزعمون أنك لا تحسن تصلي قال أبو إسحاق أما أنا والله فإني كنت أصلي بهم صلاة رسول الله ﷺ ما أخرم عنها أصلي صلاة العشاء فأركد في الأوليين وأخف في الأخريين قال ذاك الظن بك يا أبا إسحاق فأرسل معه رجلا أو رجالا إلى الكوفة فسأل عنه أهل الكوفة ولم يدع مسجدا إلا سأل عنه ويثنون معروفا حتى دخل مسجدا لبني عبس فقام رجل منهم يقال له أسامة بن قتادة يكنى أبا سعدة قال أما إذ نشدتنا فإن سعدا كان لا يسير بالسرية ولا يقسم بالسوية ولا يعدل في القضية قال سعد أما والله لأدعون بثلاث اللهم إن كان عبدك هذا كاذبا قام رياء وسمعة فأطل عمره وأطل فقره وعرضه بالفتن وكان بعد إذا سئل يقول شيخ كبير مفتون أصابتني دعوة سعد قال عبد الملك فأنا رأيته بعد قد سقط حاجباه على عينيه من الكبر وإنه ليتعرض للجواري في الطرق يغمزهن