Abraham lived on earth worshipping Allah and calling people to monotheism, but he was journeying to Allah, knowing that his days on earth were limited and that they would be followed by death, and finally, resurrection. The knowledge of life after death filled Abraham with peace, love, and certitude.
One day, he begged Allah to show him how He brought the dead back to life. Allah commanded Abraham to take four birds, cut them up, mingle their body parts, divide them into four portions, and place them on top of four different hills, then call back the birds in Allah's name. Abraham did as he was told. Immediately the mingled parts of the birds separated to join their original bodies in different places, and the birds flew back to Abraham.
Almighty Allah revealed: And (remember) when Abraham said: 'My Lord! Show me how You give life to the dead." Allah said: "Do you not believe?" Abraham said: "Yes (I believe), but to be stronger in Faith." He said: "Take four birds, then cause them to incline towards you (then slaughter them, cut them into pieces), and then put a portion of them on every hill, and call them, they will come to you in haste. And know that Allah is All-Mighty, All-Wise." Surah 2: 260