“The Messenger of Allah (ﷺ) said: ‘The dust in the cause of Allah and the smoke of Hell will never be combined in the lungs of a slave, and the stinginess and faith can never be combined in a slave’s heart.”
That the Messenger of Allah (ﷺ) said: “When you see someone selling or buying in the Masjid then say: ‘May Allah not profit your business.’ And when you see someone announcing about something lost then say: ‘May Allah not return it to you.'” The Hadith of Abu Hurairah is Hasan Gharib. This is acted upon according to some of the people of knowledge. They dislike selling and buying in the Masjid. This is the view of Ahmad and Ishaq. Some of the people of knowledge permitted selling and buying in the Masjid.
That ‘Umar would not take the Jizyah from the Zoroastrians until ‘Abdur-Rahman bin ‘Awf informed him that the Prophet (ﷺ) took Jizyah from the Zoroastrians of Hajar.” There is more dialogue in the Hadith than this. And this Hadith is Hasan Sahih.
“I came to the Prophet (ﷺ) and said: ‘O Prophet of Allah, I am the man who came to you last year.’ He said: ‘Why do I see your body so thin (and weak)?’ He said: ‘O Messenger of Allah! I do not eat during the day; I only eat at night.’ He said: ‘Who commanded you to punish yourself?’ I said: ‘O Messenger of Allah! I am strong enough.’ He said: ‘Fast the month of patience* and one day after it.’ I said: ‘I am strong enough (to do more).’ He said: ‘Fast the month of patience and two days after it.’ I said: ‘I am strong enough (to do more).’ He said: ‘Fast the month of patience and three days after it, and fast the sacred months.’”