The brothers of the Prophet (ﷺ) are those who believed and never saw him

—The brothers of the Prophet (ﷺ)
are those who believed and never saw him

Anas ibn Malik reported:
The Messenger of Allah, (ﷺ), said, “I wish I could meet my brothers.” The Prophet’s companions said, “Are we not your brothers?” The Prophet said, “You are my companions, but my brothers are those who have faith in me although they never saw me.”

Musnad Ahmad 12169

—The Distinctive marks of a believer
for Wudu at Al Kauthar

Abu Huraira reported:
Verily Allah’s Messenger (ﷺ) said: My Cistern has its
dimensions wider than the distance between Aila and Aden, and its water is whiter than ice and sweeter than the honey diluted with milk, and its cups are more numerous than the numbers of the stars. Verily I shall prevent the (faithless) people therefrom just as a man prevents the camels of the people from his fountain. They said: Messenger of Allah,
will you recognise us on that day? He said: Yes, you will have distinctive marks which nobody among the peoples (except you) will have; you would come to me with blazing forehead and bright hands and feet on account of the traces of ablution.

Sahih Muslim 247a