Musnad Ahmad 1395
It was narrated from Moosa bin Talhah that his father said:
The Messenger of Allah (ﷺ) passed by some people who were at the top of the palm trees. He said: `What are these people doing?` They said: “They are pollinating (the trees), putting the male with the female.” He said: `I do not think this can help in any way.” They were told about that and they stopped doing it. News of that reached the Messenger of Allah (ﷺ) and he said: “If it will benefit them, then let them do it. It was only a passing thought. Do not blame me for a mere thought, but if I tell you anything about Allah (may He be glorified and exalted) then accept it from me, for I will never tell a lie about Allah.`
حَدَّثَنَا بَهْزٌ، وَعَفَّانُ، قَالَا حَدَّثَنَا أَبُو عَوَانَةَ، عَنْ سِمَاكٍ، عَنْ مُوسَى بْنِ طَلْحَةَ، عَنْ أَبِيهِ، قَالَ مَرَّ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ عَلَى قَوْمٍ فِي رُءُوسِ النَّخْلِ فَقَالَ مَا يَصْنَعُ هَؤُلَاءِ قَالُوا يُلَقِّحُونَهُ يَجْعَلُونَ الذَّكَرَ فِي الْأُنْثَى قَالَ مَا أَظُنُّ ذَلِكَ يُغْنِي شَيْئًا فَأُخْبِرُوا بِذَلِكَ فَتَرَكُوهُ فَأُخْبِرَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَقَالَ إِنْ كَانَ يَنْفَعُهُمْ فَلْيَصْنَعُوهُ فَإِنِّي إِنَّمَا ظَنَنْتُ ظَنًّا فَلَا تُؤَاخِذُونِي بِالظَّنِّ وَلَكِنْ إِذَا أَخْبَرْتُكُمْ عَنْ اللَّهِ عَزَّ وَجَلَّ بِشَيْءٍ فَخُذُوهُ فَإِنِّي لَنْ أَكْذِبَ عَلَى اللَّهِ شَيْئًا‏.‏