Vayera 

וירא

After Abraham was commanded not to slaughter Isaac, he saw a ram whose horns were entangled in branches, and he sacrificed it to God in place of Isaac. The Sages explain that this ram symbolizes the future fate of Israel in enslavement and redemption. 

Throughout that day, Abraham would see a ram entangled in a tree then untangled itself and escape, entangled in a thicket then untangled itself and escape. The Holy One, blessed be He, said to him: Abraham, your children are destined to be so. They will be entangled in their iniquities and enmeshed, or enslaved, with the gentile kingdoms, from Babylonia to Media, from Media to Greece, and from Greece to Edom, Rome. Abraham said before Him: Master of the Universe, will it be so forever? God said to him: Ultimately, they will be redeemed with the horns of this ram [as the verse states with regard to the future redemption]: “And the Lord God will sound the shofar, and He will go with the storms to the south” (Zechariah 9:14). <source>(Jerusalem Talmud, <i>Ta’anit</i> 10:2) </source>