(a) Sayyiduna Abu Musa (may Allah be pleased with him) said: I came to the Prophet (peace and blessings be upon him) while he had camped at al-Batha, and he said to me: "How did you say the talbiyah?" I said: 'Labbayk bi-ihlalin ka-ihlal al-Nabi' (Here I am, with an ihlal like the ihlal of the Prophet (peace and blessings be upon him)). He said: "You did well. Perform tawaf of the House and between Safa and Marwah, then come out of ihram," and he narrated the long hadith.
(b) In the narration of Tawus: The Prophet (peace and blessings be upon him) set out from Madinah without naming either Hajj or Umrah, awaiting the decision (revelation). The revelation came down to him while he (peace and blessings be upon him) was between Safa and Marwah, so he ordered those of them who had entered ihram and had no sacrificial animal with them to make it an Umrah.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 8688