"I heard 'Umar say: "The Messenger of Allah (ﷺ), said: 'Gold for silver is usury, unless it is exchanged on the spot."' (Sahih) Abu Bakr bin Abu-Shaibah said: "I heard sufyan saying: 'Gold for silver." memorize (this).
Sunan Ibn Majah Book 12, Hadith 123
← Previous Hadith "I heard him meaning Ibn 'Abbas allowing exchange (of Dirhams for Dirham etc., if extra was given) and that was narrated from him. Then I heard that he has taken back this opinion. I met him in Makkah and said: 'I heard that you had taken back (your opinion).' He said: 'Yes. That was just my own opinion, but Abu Sa'eed narrated from the Messenger of Allah (ﷺ) that he forbade exchange (of like items if extra is given)."'

Sunan Ibn Majah Book 12, Hadith 122 Next Hadith → "I came saying. 'Who will exchange Dirham?' Talhah bin 'Ubaidullah, who was with 'Umar bin Khattab, said: 'Show us your gold, then come to us; when our treasure comes, we will give you your silver.' 'Umar said: 'No, by Allah, you will give him silver (now), or give him back his gold, for the Messenger of Allah (ﷺ) said: "Silver for gold is usury, unless it is exchanged on the spot."'

Sunan Ibn Majah Book 12, Hadith 124