Harb ibn Ubaydullah told on the authority of his grandfather, his mother's father, that he had it on the authority of his father that the Messenger of Allah ﷺ said: Tithes are to be levied on Jews and Christians, but not on Muslims.  

قَالَ رَسُولُ اللَّهِ ﷺ إِنَّمَا الْعُشُورُ عَلَى الْيَهُودِ وَالنَّصَارَى وَلَيْسَ عَلَى الْمُسْلِمِينَ عُشُورٌ  

A man reported from Bakr bin Wa’il on the authority of his maternal uncle as saying, I said “Apostle of Allaah ﷺ may I levy tithe on my people.?” He replied “Tithes are to be levied on Jews and Christians.” (Using translation from Abū Dāʾūd 3048)   

قُلْتُ يَا رَسُولَ اللهِ أَعْشِرُ قَوْمِي؟ قَالَ إِنَّمَا الْعُشُورُ عَلَى الْيَهُودِ وَالنَّصَارَى وَلَيْسَ عَلَى أَهْلِ الْإِسْلَامِ عُشُورٌ  

[Machine] "The Taqafiyyah man from the tribe of Banu Taghlib, Abu Umayyah, narrated that he heard the Prophet ﷺ saying, 'Muslims do not have to pay Ushur (one-tenth) as it is only applicable to Jews and Christians.'"  

الثَّقَفِيِّعَنْ أَبِي أُمِّية رَجُلٌ مِنْ بَنِي تَغْلِبَ أَنَّهُ سَمِعَ النَّبِيَّ ﷺ يَقُولُ لَيْسَ عَلَى الْمُسْلِمِينَ عُشُورٌ إِنَّمَا الْعُشُورُ عَلَى الْيَهُودِ وَالنَّصَارَى  

A man reported from Bakr bin Wa’il on the authority of his maternal uncle as saying, I said “Apostle of Allaah ﷺ may I levy tithe on my people.?” He replied “Tithes are to be levied on Jews and Christians.” (Using translation from Abū Dāʾūd 3048)   

قُلْتُ يَا رَسُولَ اللهِ أُعْشِرُ قَوْمِي؟ فَقَالَ إِنَّمَا الْعُشُورُ عَلَى الْيَهُودِ وَالنَّصَارَى وَلَيْسَ عَلَى الْإِسْلَامِ عُشُورٌ  

"ليسَ عَلى الْمُسْلِمين عُشورٌ، إِنَّمَا الْعشور عَلى اليَهود وَالنَّصَارَى".  

"إِنَّما العشورُ على اليهودِ والنصارى، وليس على المسلمين عُشُورٌ".