Narrated Ubayy ibn Ka'b:

The Messenger of Allah (ﷺ) commissioned me as a collector of zakat. I visited a man. When he had collected his property of camels, I found that a she-camel in her second year was due from him. I said to him: Pay a she-camel in her second year, for she is to be paid as sadaqah (zakat) by you. He said: That one is not worthy of milking and riding. Here is another she-camel which is young, grand and fat. So take it. I said to him: I shall not take an animal for which I have not been commanded. The Messenger of Allah (ﷺ) is here near to you. If you like, go to him, and present to him what you presented to me. Do that; if he accepts it from you, I shall accept it; if he rejects it, I shall reject it. He said: I shall do it. He accompanied me and took with him the she-camel which he had presented to me. We came to the Messenger of Allah (ﷺ). He said to him: Prophet (ﷺ) of Allah, your messenger came to me to collect zakat on my property. By Allah, neither the Messenger of Allah nor his messenger has ever seen my property before. I gathered my property (camels), and he estimated that a she-camel in her second year would be payable by me. But that has neither milk nor is it worth riding. So I presented to him a grand young she-camel for acceptance as zakat. But he has refused to take her. Look, she is here; I have brought her to you, Messenger of Allah. Take her. The Messenger of Allah (ﷺ) said: That is what is due from you. If you give voluntarily a better (animal) Allah will give a reward to you for it. We accept her from you. She is here, Messenger of Allah; I have brought her to you. So take her. The Messenger of Allah (ﷺ) then ordered me to take possession of it, and he prayed for a blessing on his property.

حَدَّثَنَا مُحَمَّدُ بْنُ مَنْصُورٍ، حَدَّثَنَا يَعْقُوبُ بْنُ إِبْرَاهِيمَ، حَدَّثَنَا أَبِي، عَنِ ابْنِ إِسْحَاقَ، قَالَ حَدَّثَنِي عَبْدُ اللَّهِ بْنُ أَبِي بَكْرٍ، عَنْ يَحْيَى بْنِ عَبْدِ اللَّهِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ سَعْدِ بْنِ زُرَارَةَ، عَنْ عُمَارَةَ بْنِ عَمْرِو بْنِ حَزْمٍ، عَنْ أُبَىِّ بْنِ كَعْبٍ، قَالَ بَعَثَنِي النَّبِيُّ صلى الله عليه وسلم مُصَدِّقًا فَمَرَرْتُ بِرَجُلٍ فَلَمَّا جَمَعَ لِي مَالَهُ لَمْ أَجِدْ عَلَيْهِ فِيهِ إِلاَّ ابْنَةَ مَخَاضٍ فَقُلْتُ لَهُ أَدِّ ابْنَةَ مَخَاضٍ فَإِنَّهَا صَدَقَتُكَ ‏.‏ فَقَالَ ذَاكَ مَا لاَ لَبَنَ فِيهِ وَلاَ ظَهْرَ وَلَكِنْ هَذِهِ نَاقَةٌ فَتِيَّةٌ عَظِيمَةٌ سَمِينَةٌ فَخُذْهَا ‏.‏ فَقُلْتُ لَهُ مَا أَنَا بِآخِذٍ مَا لَمْ أُومَرْ بِهِ وَهَذَا رَسُولُ اللَّهِ صلى الله عليه وسلم مِنْكَ قَرِيبٌ فَإِنْ أَحْبَبْتَ أَنْ تَأْتِيَهُ فَتَعْرِضَ عَلَيْهِ مَا عَرَضْتَ عَلَىَّ فَافْعَلْ فَإِنْ قَبِلَهُ مِنْكَ قَبِلْتُهُ وَإِنْ رَدَّهُ عَلَيْكَ رَدَدْتُهُ ‏.‏ قَالَ فَإِنِّي فَاعِلٌ فَخَرَجَ مَعِي وَخَرَجَ بِالنَّاقَةِ الَّتِي عَرَضَ عَلَىَّ حَتَّى قَدِمْنَا عَلَى رَسُولِ اللَّهِ صلى الله عليه وسلم فَقَالَ لَهُ يَا نَبِيَّ اللَّهِ أَتَانِي رَسُولُكَ لِيَأْخُذَ مِنِّي صَدَقَةَ مَالِي وَايْمُ اللَّهِ مَا قَامَ فِي مَالِي رَسُولُ اللَّهِ صلى الله عليه وسلم وَلاَ رَسُولُهُ قَطُّ قَبْلَهُ فَجَمَعْتُ لَهُ مَالِي فَزَعَمَ أَنَّ مَا عَلَىَّ فِيهِ ابْنَةُ مَخَاضٍ وَذَلِكَ مَا لاَ لَبَنَ فِيهِ وَلاَ ظَهْرَ وَقَدْ عَرَضْتُ عَلَيْهِ نَاقَةً فَتِيَّةً عَظِيمَةً لِيَأْخُذَهَا فَأَبَى عَلَىَّ وَهَا هِيَ ذِهِ قَدْ جِئْتُكَ بِهَا يَا رَسُولَ اللَّهِ ‏.‏ خُذْهَا فَقَالَ لَهُ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏

‏ ذَاكَ الَّذِي عَلَيْكَ فَإِنْ تَطَوَّعْتَ بِخَيْرٍ آجَرَكَ اللَّهُ فِيهِ وَقَبِلْنَاهُ مِنْكَ ‏

‏ ‏.‏ قَالَ فَهَا هِيَ ذِهِ يَا رَسُولَ اللَّهِ قَدْ جِئْتُكَ بِهَا فَخُذْهَا ‏.‏ قَالَ فَأَمَرَ رَسُولُ اللَّهِ صلى الله عليه وسلم بِقَبْضِهَا وَدَعَا لَهُ فِي مَالِهِ بِالْبَرَكَةِ ‏.‏