It is a divine inspiration.
Translation endnotes
[53:1-18] The extraordinary event told in these verses, as it appears, is a miraculous experience. Is the falling of stars an apparent perception because of traveling among galaxies faster than speed of light? What were the signs Muhammed witnessed? Did Muhammed meet God or Gabriel? 20:114. [53:3-4] Meccan idol worshipers claimed that Muhammed was the author of the Quran (25:5; 68:15). The beginning of Chapter 53 is about the revelation of the Quran. It states that "the Quran is from Him." It is not Muhammed's personal claim; it is a divine statement. Therefore, claiming that the pronoun "it" in the verse 53:4 refers to the words of Muhammed, not of God, is an obvious distortion. According to the above verse, "it" is revelation, without exception. This can be valid only for the Quran. It is nonsense to claim that Muhammed's daily conversation was entirely revelation. For example, God firmly criticizes Muhammed's words to Zayd (33:37). Obviously, the criticism was not about revelation. The beginning phrase of Chapter 97 informs us about the revelation of the Quran: "We revealed it in the Night of Destiny." The "it" in this verse is the same as the "it" in 53:4. . .