The Light of Muhammad sawas and Ali a.s

 

The light of Prophet Muhammad and his family (peace be upon them all) was the first creation of Allah, and is even acknowledged by the Sunnis.
Of the traditions they have narrated in this regard is the following hadith on the authority of Salman al-Farsi (a.s) who said:

"I heard the Apostle of Allah (pbuhap) saying: "I and Ali were one light in the hands of Allah fourteen thousand years (14,000) before He created Adam (a.s). When Allah created Adam (a.s). He divided that light into two parts, I being one part and Ali being the other."

Sunni References:
-Mizan al-I'tidal, by al-Dhahabi, v1, p235
-Fadha'il al-Sahaba, by Ahmad Ibn Hanbal, v2, p663, Tradition Nu-1130
-Al-Riyadh al-Nadhira, by Muhibbuddin al-Tabari, v2, p164, v3, p154
-History of Ibn Asakir

Seeing Allah swt by the heart means recognition/identification (Ma'rifa) of Allah through the heart. Now, according to the following traditions, the recognition of Allah is defined as the recognition of the light of Prophet Muhammad and his Ahlul-Bayt, peace be upon them. 

Salman al-Farsi (a.s) and Abu Dhar (a.s) both narrated:
The Leader of the Faithful (a.s) said:

"Certainly, no one's faith becomes complete until he knows me by the recognition of my light. Once he knows me by such recognition (Ma'rifat), his heart has passed Allah's test for (perfect) faith and Allah has opened his bosom for submission and has become cognizant (Arif) with vision. He who falls short of such recognition will (remain) doubtful. O Salman! O Jundab! Recognition (Ma'rifat) of my light is recognition of Allah swt, and recognition of Allah swt is recognition of my light."

{Bihar al-Anwar, v26, p1, Hadith #1}

Imam al-Reza (a.s) said: "Allah is known/recognized by the signs and is proven by the indications."

-Tafsir Imam Hasan al-Askari (AS), p50, Hadith #24
-Kitab al-Tawhid, p47, Hadith #9
-Bihar al-Anwar, v4, p303, Hadith #31

The greater the sign, the greater the recognition. A person who has recognized the greatest sign of Allah (i.e., the light of the Prophet (pbuhap) and his Ahlul-Bayt (a.s.), has attained the greatest recognition (Ma'rifat) of Allah.

Muhammad Ibn Muslim narrated:
Imam al-Baqir (a.s) said: "Avoid pondering on (the Essence of) Allah. However, when you intend to look towards His Majesty, then look towards His greatest creation."

-al-Kafi, v1, p93, Hadith #7
-Kitab al-Tawhid, p457, Hadith #14
-Wasa'il al-Shia, v16, p195, Hadith #21327