What are you doing? They said: We are grafting them, whereupon he said: It may perhaps be good for you if you do not do that, so they abandoned this practice (and the date-palms) began to yield less fruit. They made a mention of it (to the Holy Prophet), whereupon he said: I am a human being, so when I command you about a thing pertaining to religion, do accept it, and when I command you about a thing out of my personal opinion, keep it in mind that I am a human being. 'Ikrima reported that he said something like this. (Using translation from Muslim 2362)   

قَدِمَ رَسُولُ اللهِ ﷺ الْمَدِينَةَ وَهُمْ يُؤَبِّرُونَ النَّخْلَ يَقُولُ يُلَقِّحُونَ قَالَ «مَا تَصْنَعُونَ؟» قَالُوا كُنَّا نَصْنَعُهُ قَالَ «لَوْ لَمْ تَفْعَلُوا كَانَ خَيْرًا» فَتَرَكُوهَا فَشِيصَتْ فَذُكِرَ ذَلِكَ لَهُ فَقَالَ «إِنَّمَا أَنَا بَشَرٌ فَإِذَا أَمَرْتُكُمْ بِشَيْءٍ مِنْ دِينِكُمْ فَخُذُوا بِهِ وَإِذَا أَمَرْتُكُمْ بِشَيْءٍ مِنْ دُنْيَاكُمْ فَإِنَّمَا أَنَا بَشَرٌ»  

Rafi bin Khadij and Sahl Bi Abi Hathamah narrated that the Messenger of Allah forbade Muzabanah, which means selling fresh dates still on the tree for dried dates, except in cases of 'Araya, for which he gave permission. (Sahih (Using translation from Nasāʾī 4543)   

أَنَّ رَسُولَ اللهِ ﷺ نَهَى عَنِ الْمُزَابَنَةِ وَالْمُزَابَنَةُ التَّمْرُ بِالتَّمْرِ إِلَّا أَصْحَابَ الْعَرَايَا فَإِنَّهُ قَدْ أَذِنَ لَهُمْ  

[Machine] "The Messenger of Allah ﷺ forbade the selling of ripe dates for dried dates, but allowed the people of the land to buy them with their dried dates that they would eat."  

«نَهَى رَسُولُ اللهِ ﷺ عَنْ بَيْعِ الرُّطَبِ بِالتَّمْرِ وَرَخَّصَ فِي الْعَرِيَّةِ أَنْ يَشْتَرِيَهَا أَهْلُهَا بِخَرْصِهَا بِتَمْرٍ يَأْكُلُونَهُ»