Al-Khallāl narrates in his Kitāb al-Sunnah, citing Ahmad ibn Ḥanbal through a report from al-Zuhrī, who said:

“When Moses heard the speech of Allah he said, ‘My Lord, this speech that I am hearing— is it truly Your speech?’

Allah replied, ‘Yes, Moses, it is My speech. I have addressed you with the power of ten thousand tongues, while I possess the power of every tongue and am mightier still. I have spoken to you only in proportion to what your body can endure; had I spoken to you with more than this, you would have perished.’

When Moses returned to his people they said, ‘Describe for us the speech of your Lord.’

He answered, ‘Glory be to Allah! How could I possibly describe it to you?’

They said, ‘Then give us an analogy.’

He said, ‘Have you ever heard the crashing sound of thunderbolts when they come with the sweetest tone you have ever heard? It is something like that.’”

As for the Messiah, peace be upon him, every person could hear his voice