Abu Sa'id al-Khudri reported Allah's Messenger (ﷺ) as saying: Do not sell gold for gold, except like for like, and don't increase something of it upon something; and don't sell silver unless like for like, and don't increase some thing of it upon something, and do not sell for ready money something to be given later.
Nafi' reported that a person of the tribe of Laith told Ibn 'Umar that Abu Sa'id al-Khudri narrated it from the Messenger of Allah (ﷺ). In the narration of Qutaiba: So 'Abdullah went and Nafi' with him, and in the hadith transmitted by Ibn Rumh (the words are) that Nafi' said: 'Abdullah (b. 'Umar) went, and I and the person belonging to Banu Laith along with him, until he entered (the house) of Abu Sa'id al-Khudri, and he ('Abdullah bin 'Umar (RA)) said: This (man) has informed me that you report that Allah's Messenger (ﷺ) forbade the sale of silver for silver except in case of like for like, and sale of gold for gold except in case of like for like. Abu Sa'id pointed towards his eyes and his ears with his fingers and said: My eyes saw, and my ears listened to Allah's Messenger (ﷺ) saying: Do not sell gold for gold, and do not sell silver for silver except in case of like for like, and do not increase something of it upon something, and do not sell for ready money something of it not present, but hand to hand.
Abu Sa'id al-Khudri (RA) reported Allah's Messenger (ﷺ) as saying: Do not sell gold for gold and silver for silver except weight for weight and of the same quality.