Please let me now if there is any authentic source where this incident of the sun not rising because of Bilal (may Allah be pleased with him) is mentioned.
There is no proof that the sun was held back for anyone except the Prophet of Allah Yoosha‘ ibn Noon (peace be upon him). In fact the Prophet (peace and blessings of Allah be upon him) stated that this did not happen to anyone other than Yoosha‘ ibn Noon (peace be upon him). This is seen in the hadeeth (narration) of Abu Hurayrah (may Allah be pleased with him), according to which the Prophet (peace and blessings of Allah be upon him) said: “One of the Prophets went out on a campaign… and he approached a town at the time of ‘Asr (late afternoon) prayer, or close to that time. He said to the sun: You are under the command of Allah and I am under the command of Allah. O Allah, halt it for me for a while. So it was halted for him until Allah granted him victory.”
Narrated by al-Bukhari (3124) and Muslim (1747).
In the version narrated by al-Imam Ahmad in al-Musnad (14/65) it says:
“The sun was not held back for any person except Yoosha‘ (peace be upon him) on the day he was marching to Jerusalem.
Al-Shaykh al-Albani (may Allah have mercy on him) said:
This indicates that the sun was not held back for anyone except for Yoosha‘ (peace be upon him). This is indicative of the weakness of the reports which suggest that happened for anyone else.
It is appropriate to quote what we have come across concerning this …
Then the Shaykh (may Allah have mercy on him) mentioned what has been narrated about the same being held back for people other than Yoosha‘ ibn Noon (peace be upon him) and explained what is wrong with these reports. Then he said:
To sum up, there is no saheeh (authentic) report about the sun being held back at all except this saheeh hadeeth. End quote.
Al-Silsilah al-Saheehah (no.202)
To conclude, we have not come across any basis for the story about the sun being held back from rising until Bilaal (may Allah be pleased with him) called the adhan, in any saheeh or da‘eef (weak) report, or even in any fabricated (mawdoo‘) hadeeth that is known.
It is not permissible to speak of such things except on the basis of sound proof and evidence. Otherwise it is speculation, and speaking about Allah without knowledge.
And Allah knows best.