<P> The plagues seemed to affect "all the land of Egypt", but the children of Israel were unaffected . For the last plague, the Torah indicates that they were only spared from the final plague by sacrificing the Paschal lamb, marking their place directly above their doors with the lamb's blood, and hastily eating the roasted sacrifice together with unleavened bread (now known as Matzoh) which they took from their ovens in haste, as they made ready for the Exodus . The Torah describes God as actually passing through Egypt to kill all firstborn children and cattle, but passing over (hence "Passover") houses which have the sign of lambs' blood on the doorpost . It is debated whether it was actually God who came through the streets or one of his angels . Some also think it may be the Holy Spirit . It is most commonly known as the "Angel of Death". The night of this plague, Pharaoh finally relents and sends the Israelites away under their terms . </P> <P> After the Israelites leave en masse, a departure known as The Exodus, God introduces himself by name and makes an exclusive covenant with the Israelites on the basis of this miraculous deliverance . The Ten Commandments encapsulate the terms of this covenant . Joshua, the successor to Moses, reminds the people of their deliverance through the plagues . According to 1 Samuel, the Philistines also knew of the plagues and feared their author . Later, the psalmist sang of these events . </P> <P> The Torah also relates God's instructions to Moses that the exodus of the Israelites from Egypt must be celebrated yearly on the holiday of Passover (Pesaḥ פסח); the rituals observed on Passover recall the events surrounding the exodus from Egypt . The month of Nisan has become important to the Jews . The Torah additionally cites God's sparing of the Israelite firstborn as a rationale for the commandment of the redemption of the firstborn . This event is also commemorated by the Fast of the Firstborn on the day preceding Passover but which is traditionally not observed because a siyum celebration is held which obviates the need for a fast . </P> <P> It seems that the celebration of Passover waned from time to time, since other biblical books provide references to revival of the holiday . For example, it was reinstated by Joshua at Gilgal, by Josiah, by Hezekiah and, after the return from the captivity, by Ezra . By the time of the Second Temple it was firmly established in Israel . </P>

What was the fifth plague sent on egypt