When is it obligatory for the pilgrim performing Tamattu' Hajj to sacrifice the Hady, and does the Hady multiply with multiple 'Umrahs performed before Hajj?

"The ihram of a pilgrim from Egypt before the miqat is permissible according to the majority of scholars, even if it is contrary to the Sunnah. As for the mutamatti' (pilgrim performing Hajj tamattu'), he should not sacrifice the hady (sacrificial animal) except on the Day of Nahr (10th of Dhul-Hijjah) and the two or three days that follow it, and this is the view of the majority of scholars. If a mutamatti' performs more than one 'umrah before entering ihram for Hajj, he is only required to offer one hady, which he sacrifices on the Day of Nahr."