who dressed them in coats of iron and left them to bake beneath the scorching sun. Not one of them remained without yielding to whatever the idolaters wanted—save Bilal. He counted his own life as insignificant for Allah’s sake, and his people likewise thought little of him, so they turned him over to the children. The youngsters dragged him through the ravines of Mecca while he kept saying, “ahad, ahad (He is One, He is One).” (1)

This report is also supported by another sound chain of transmission.

Abu Hayyan al-Taymi narrated—from Abu Zurʿah—from Abu Hurayrah:
At the time of the dawn prayer the Messenger of Allah ﷺ said to Bilal, “Tell me about the deed you are most hopeful about since becoming a Muslim, for during the night I heard the shuffle of your sandals ahead of me in Paradise.”
He replied, “I know of no deed that gives me greater hope than this: whenever I perform a complete ritual ablution at any hour of the night or day, I pray for my Lord whatever has been decreed for me to pray.” (2)

Husayn ibn Waqid related: Ibn Buraydah told us—I heard my father say:
The Messenger of Allah ﷺ awoke one morning and summoned Bilal, saying, “What act enabled you to enter Paradise before me? I have never entered Paradise without hearing the rustle of your footsteps in front of me. Last night I entered Paradise, heard your footsteps before me, and came upon a palace of gold. I asked, ‘Whose palace is this?’ They said, ‘It belongs to ʿUmar.’”
Bilal answered, “I have never given the call to prayer without then praying two rakʿahs, and whenever I fall into a state of minor impurity I immediately perform ablution, and I regard it as a duty to Allah that I perform two rakʿahs afterward.”
He ﷺ said, “It is because of that.” (3)