A man came to Allah's Messenger (ﷺ) asking him about Islam, Allah's Messenger (ﷺ) said, "You have to offer five compulsory prayers in a day and a night (24 hours)." The man asked, "Is there any more compulsory prayers for me?" Allah's Messenger (ﷺ) said, "No, unless you like to offer Nawafil (i.e. optional prayers)." Allah's Messenger (ﷺ) then added, "You have to observe fasts during the month of Ramadan." The man said, "Am I to fast any other days?' Allah's Messenger (ﷺ) said, "No, unless you wish to observe the optional fast voluntarily." Then Allah's Messenger (ﷺ) told him about the compulsory Zakat. The man asked, "Do I have to give anything besides?" Allah's Messenger (ﷺ) said, "No, unless you wish to give in charity voluntarily." So, the man departed saying, "By Allah I will neither do more nor less than that." Allah's Messenger (ﷺ) said, "If he has said the truth he will be successful."
Sahih al-Bukhari Book 52, Hadith 39
← Previous Hadith The Prophet (ﷺ) said, "Whoever takes a false oath in order to grab another man's (or his brother's) property, then Allah will be angry with him when he will meet him." Then Allah confirmed this by revealing the Divine Verse: "Verily! Those who purchase a little gain at the cost of Allah's Covenant and their oaths . . . Will get painful punishment." (3.77) Al-Ash'ath met me and asked, "What did `Abdullah tell you today?" I said, "So and so." He said, "The Verse was revealed regarding my case."

Sahih al-Bukhari Book 52, Hadith 38 Next Hadith → The Prophet (ﷺ) said, "Whoever has to take an oath should swear by Allah or remain silent." (i.e. He should not swear by other than Allah.)

Sahih al-Bukhari Book 52, Hadith 40