Sahih Muslim Book 7, Hadith Number 2814.
Chapter : Permissibility of saying one has entered into Ihram like the Ihram of the other one or Abrogation of putting off Ihram and completing (Hajj and Umra).
Abu Musa, (Allah be pleased with him) reported that he used to deliver religious verdict in favour 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 beads.