Jabir bin Samurah (May Allah be pleased with them) said

The inhabitants of Kufah complained to 'Umar (May Allah be pleased with him) against Sa'd bin Abu Waqqas (May Allah be pleased with him) and 'Umar (May Allah be pleased with him) appointed 'Ammar (May Allah be pleased with him) as Governor of Kufah in his place. Their complaint was that he did not even conduct As-Salat (the prayers) properly. 'Umar (May Allah be pleased with him) sent for Sa'd and said to him: "O Abu Ishaq, the people claim that you do not offer the Salat properly." Sa'd replied: "By Allah! I observe Salat according to the Salat of the Messenger of Allah (ﷺ), and I make no decrease in it. I prolong Qiyam (standing) in the first two Rak'ah in Maghrib and 'Isha' prayers and shorten in the last ones." 'Umar (May Allah be pleased with him) said: "This is what I thought of you, O Abu Ishaq!" Then he sent with him a man (or some men) to Kufah to investigate the matter about him (from the people of Kufah). The inquiry was conducted in every mosque and all the people in these mosques praised him; but in the mosque of the Banu 'Abs, a man, with the name of Usamah bin Qatadah and surname Abu Sa'dah, stood up and said, "Sa'd bin Abu Waqqas did not participate in Jihad and he did not distribute the spoils equitably and did not judge justly." On this Sa'd said: "I shall make three supplications in respect of him: O Allah! If this slave of Yours is a liar and seeker of notoriety, please prolong his life and lengthen his period of adversity and afflict him with trials." (And so did it happen.) Thereafter, when the man was asked about his condition he would say, "I am an old man afflicted with trials and overtaken by the curses of Sa'd."

'Abdul-Malik bin 'Umair (a subnarrator) said: I saw this man with eyebrows hung over his eyes as a result of his old age and he walked aimlessly, following young girls and winking at them.

[Al-Bukhari and Muslim].