The Talbiyah, its description and timing

'Abdullah b. 'Umar (Allah be pleased with them) reported: I heard the Messenger of Allah (ﷺ) pronouncing Talbiya with compacted hair: Here I am at Thy service. O Allah: here I am at Thy service; here I am at Thy service. There is no associate with Thee; here I am at Thy service. Verily all praise and grace is due to Thee and the Sovereignty (too). There is no associate with Thee; and he did not make any addition to these words. 'Abdullah b. 'Umar (Allah be pleased with them) (further) said: The Messenger of Allah (ﷺ) used to offer two rak'ahs of prayer at Dhu'l-Hulaifa and then when his camel stood up with him on its back near the mosque at Dhu'l-Hulaifa, he pronounced these words (of Talbiya). And 'Abdullah b. 'Umar (Allah be pleased'with them) said that 'Umar b. Khattab (Allah be pleased with him) pronounced, the Talbiya of the Messenger of Allah (ﷺ) in these words of his (Prophet's words) and said: Here I am at Thy service, O Lord; here I am at Thy service, ready to obey Thee, and good is in Thy Hand, Here I am at Thy service. Unto Thee is the petition and deed (is also for Thee).