Ibn Majah

‘Abdullah bin ‘Umar (may Allah be pleased with them) says: I used to sell camels in the market of Baqi‘. I would sell them for dinars and take silver in exchange, and I would sell them for silver and take dinars in exchange. I came to the Messenger of Allah (peace be upon him) and saw that he was coming out of the house of Hafsah (may Allah be pleased with her), so I asked him about this. He said: “There is no harm in doing so at the current price.” © Imam Tirmidhi says:
1- We know this hadith as being marfu‘ only from the narration of Simak bin Harb,
2- Simak narrated it from Sa‘id bin Jubair, and Sa‘id from Ibn ‘Umar, and Dawud bin Abi Hind narrated this hadith from Sa‘id bin Jubair, and Sa‘id from Ibn ‘Umar as mawquf,
3- Some people of knowledge act upon this hadith, that if someone takes silver in exchange for gold or gold in exchange for silver, there is no harm in it. This is also the opinion of Ahmad and Ishaq,
4- And some people of knowledge among the Companions and others considered it disliked.

Narrated Abdullah ibn Umar: I used to sell camels at al-Baqi for dinars and take dirhams for them, and sell for dirhams and take dinars for them. I would take these for these and give these for these. I went to the Messenger of Allah ﷺ who was in the house of Hafsah. I said: Messenger of Allah, take it easy, I shall ask you (a question): I sell camels at al-Baqi'. I sell (them) for dinars and take dirhams and I sell for dirhams and take dinars. I take these for these, and give these for these. The Messenger of Allah ﷺ then said: There is no harm in taking them at the current rate so long as you do not separate leaving something to be settled.

´It was narrated that Ibn 'Umar said:` "I used to sell camels, and I used to buy gold for silver and silver for gold, Dinar for Dirham and Dirham for Dinar. I asked the Prophet (ﷺ) about that, and he said: 'If you take one of them and give the other, then you and your companion should not separate until everything is clear (i.e., the exchange is completed).’” (Hasan) Another chain with similar wording.

Narrated [Ibn 'Umar (RA)]: I said, "O Allah's Messenger, I sell camels at al-Baqi'. I sell for Dinars and take Dirhams (for them), and sell for Dirhams, and take Dinars (for them), I take this for that and give that for this (i.e. Dinars and Dirhams)." Allah's Messenger (ﷺ) replied, "There is no harm in taking them at the current rate so long as you do not separate leaving something still to be settled (from the exchange)." [Reported by al-Khamsah and al-Hakim graded it Sahih (authentic)].