Abu Musa, (Allah be pleased with him) reported that he used to deliver religious verdict in favor of Hajj Tamattu'. A person said to him:

Exercise restraint in delivering some of your religious verdicts, for you do not know what the Commander of Believers has introduced in the rites (of Hajj) after you (when you were away in Yemen). He (Abu Musa, ) met him (Hadrat Umar) subsequently and asked him (about it), whereupon 'Umar said: I know that Allah's Apostle (May peace be upon him) and also his Companions did that (observed Tamattu'), but I do not approve that the married persons should have intercourse with their wives under the shade of the trees, and then set out for Hajj with water trickling down from their heads.
وَحَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، وَابْنُ، بَشَّارٍ قَالَ ابْنُ الْمُثَنَّى حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، حَدَّثَنَا شُعْبَةُ، عَنِ الْحَكَمِ، عَنْ عُمَارَةَ بْنِ عُمَيْرٍ، عَنْ إِبْرَاهِيمَ بْنِ أَبِي مُوسَى، عَنْ أَبِي مُوسَى، أَنَّهُ كَانَ يُفْتِي بِالْمُتْعَةِ فَقَالَ لَهُ رَجُلٌ رُوَيْدَكَ بِبَعْضِ فُتْيَاكَ فَإِنَّكَ لاَ تَدْرِي مَا أَحْدَثَ أَمِيرُ الْمُؤْمِنِينَ فِي النُّسُكِ بَعْدُ حَتَّى لَقِيَهُ بَعْدُ فَسَأَلَهُ فَقَالَ عُمَرُ قَدْ عَلِمْتُ أَنَّ النَّبِيَّ صلى الله عليه وسلم قَدْ فَعَلَهُ وَأَصْحَابُهُ وَلَكِنْ كَرِهْتُ أَنْ يَظَلُّوا مُعْرِسِينَ بِهِنَّ فِي الأَرَاكِ ثُمَّ يَرُوحُونَ فِي الْحَجِّ تَقْطُرُ رُءُوسُهُمْ ‏.‏
Reference : Sahih Muslim 1222
In-book reference : Book 15, Hadith 170
USC-MSA web (English) reference : Book 7, Hadith 2814
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