Bismillah.
Narrated Jabir bin 'Abdullah :
When my father was martyred, I lifted the sheet from his face and wept and the people forbade me to do so but the Prophet did not forbid me. Then my aunt Fatima began weeping and the Prophet said, "It is all the same whether you weep or not. The angels were shading him continuously with their wings till you shifted him (from the field). "
Prophet (SAW) knew his body was being shadowed by angels because he was shown it.
Narrated Abu Huraira,
Allah's Apostle informed (the people) about the death of An-Najashi on the very day he died. He went towards the Musalla (praying place) and the people stood behind him in rows. He said four Takbirs (i.e. offered the Funeral prayer).
Meaning, Najashi died a Muslim. Prophet (SAW) was informed about it, so he offered his funeral prayer.
Narrated Anas bin Malik:
The Prophet said, "Zaid took over the flag and was martyred. Then it was taken by Jafar who was martyred as well. Then 'Abdullah bin Rawaha took the flag but he too was martyred and at that time the eyes of Allah's Apostle were full of tears. Then Khalid bin Al-Walid took the flag without being nominated as a chief (before hand) and was blessed with victory."
Prophet (SAW) was being informed about the situation at the battlefield continuously.
Narrated Ibn Abbas.
A person died and Allah's Apostle used to visit him. He died at night and (the people) buried him at night. In the morning they informed the Prophet (about his death). He said, "What prevented you from informing me?" They replied, "It was night and it was a dark night and so we disliked to trouble you." The Prophet went to his grave and offered the (funeral) prayer.
He offered the funeral prayer, though it was late. Among the rights of Muslims upon each other is attending funeral processions.
Wassalam.