The fourth sign comes through Musa. It deepens what the third sign established. Ibrahim showed us that a substitute dies in the place of the guilty. Musa shows us that the substitute's blood is the protection. This sign is so significant that the Qur'an calls it the Great Sign.
فَأَرَىٰهُ ٱلۡأٓيَةَ ٱلۡكُبۡرَىٰ
“Then did Moses show him the Great Sign.”
Surah An-Nazi'at 79:20 | quran.com/79/20
فَأَرۡسَلۡنَا عَلَيۡهِمُ ٱلطُّوفَانَ وَٱلۡجَرَادَ وَٱلۡقُمَّلَ وَٱلضَّفَادِعَ وَٱلدَّمَ ءَايَٰتٖ مُّفَصَّلَٰتٖ فَٱسۡتَكۡبَرُواْ وَكَانُواْ قَوۡمٗا مُّجۡرِمِينَ
“So We sent upon them the flood and locusts and lice and frogs and blood as distinct signs, but they were arrogant and were a criminal people.”
Surah Al-A'raf 7:133 | quran.com/7/133
What was happening in Egypt?
Allah had sent Musa to Pharaoh with signs. Pharaoh refused. Plague after plague came. The last and most severe was the death of the firstborn in every household in Egypt. But not in every household. Allah gave the people of Musa specific instructions: take a lamb, sacrifice it, put its blood on the doorposts of the house. When the angel of judgment comes, it will pass over the house that has the blood.
What is this sign teaching?
Life was preserved by blood. The lamb died. Its blood was applied. The household was protected. Remove the blood and the household was not protected, regardless of how good or devout the people inside it were. The protection is not earned by the quality of the person inside the house. The protection comes from the blood applied outside it. Allah's provision, received or refused.
What does the blood point toward?
The same principle runs from Ibrahim's ram to Musa's lamb. A substitute. An innocent creature dying. Its death providing protection for those who receive it. The Qur'an calls the blood the Great Sign. This is the central mechanism of Allah's plan. And it is pointing forward to the one the Injil calls the Lamb of Allah: Issa al-Masih, the sinless one, whose blood is the ultimate application of this principle.
“Without the shedding of blood there is no forgiveness of sins.”
Injil, Hebrews 9:22 | bible.com/bible/111/HEB.9.22
The Injil states plainly what the Qur'an has been showing through signs. The principle established in Egypt is not historical only. It is the principle on which forgiveness itself rests.
The Mark on the Door
In a city under siege, a general sent a message to every household: paint your door with this mark before nightfall. Those whose doors bear the mark will be passed by. Those whose doors do not will not.
Some painted the mark immediately. Some debated whether it was necessary. Some were confident their upstanding character would be sufficient protection. Some simply forgot.
When nightfall came, the soldiers moved through the city exactly as the general had said. They did not knock on doors and ask about character. They did not evaluate devotion or count prayers. They looked for the mark.
In the morning, the city understood something it had not understood before: the general's word was precise. What he said would protect, protected. What he said was required, was required.
The blood on the doorpost protected regardless of the character of the people inside. The protection was in the covering, not in the covered. This is the fourth sign. Where is the blood of the momentous sacrifice applied in your life? This is the question all four signs have been building toward. Sit with it. Bring it to your prayer.