Talha bin Ubaydullah reported,

A man from the people of Najd came to the Messenger of Allah ﷺ with disheveled hair. We could hear the murmur of his voice but could not make out what he was saying until he drew near, and then it became clear that he was asking about Islam.The Messenger of Allah ﷺ said to him, "Five prayers during the day and night."The man asked, "Do I owe any others besides them?"He replied, "No, unless you wish to offer them voluntarily."The Messenger of Allah ﷺ said, "And fasting the month of Ramadan."The man asked, "Do I owe any other fasting besides it?"He replied, "No, unless you wish to fast voluntarily."Then the Messenger of Allah ﷺ mentioned zakat to him.The man asked, "Do I owe anything besides it?"He replied, "No, unless you wish to give voluntarily."The man turned away saying, "By Allah, I will not do more than this, nor less."The Messenger of Allah ﷺ said, "He has succeeded, if he is truthful."

Nasai 459

Sahih

أخبرنا قتيبة عن مالك عن أبي سهيل عن أبيه أنه سمع

طلحة بن عبيد الله يقول

جاء رجل إلى رسول الله ﷺ من أهل نجد ثائر الرأس نسمع دوي صوته ولا نفهم ما يقول حتى دنا فإذا هو يسأل عن الإسلام فقال له رسول الله ﷺ خمس صلوات في اليوم والليلة قال هل علي غيرهن قال لا إلا أن تطوع قال وصيام شهر رمضان قال هل علي غيره قال لا إلا أن تطوع وذكر له رسول الله ﷺ الزكاة قال هل علي غيرها قال لا إلا أن تطوع فأدبر الرجل وهو يقول والله لا أزيد على هذا ولا أنقص منه قال رسول الله ﷺ أفلح إن صدق

النسائي 459صحيح
Contents
Reference
Commentary
Ayat
Collection
Sunan Nasai Sughra
Book
Prayer
Chapter
How many prayers were obligated in the day and night
Numbering
Darussalam 459
Nasai 459