Surah An-Najm, The Star, 53:1-4
وَالنَّجْمِ إِذَا هَوَىٰ
I swear by the star when it goes down. (53:1) -Shakir
مَا ضَلَّ صَاحِبُكُمْ وَمَا غَوَىٰ
Your companion does not err, nor does he go astray; (53:2) -Shakir
وَمَا يَنْطِقُ عَنِ الْهَوَىٰ
Nor does he speak out of desire. (53:3) -Shakir
إِنْ هُوَ إِلَّا وَحْيٌ يُوحَىٰ
It is naught but revelation that is revealed. (53:4) -Shakir
Excerpt from Tafseer of Agha Mahdi Pooya1:
It is reported by Ibn Abbas that one night, after praying salat al- Isha’, the Holy Prophet told his companions: "At dawn, tomorrow, a star will descend on the earth from the heaven. On whomsoever's house it will come upon will be my heir, my successor, and he is the divinely commissioned guide." The star descended on Ali's house. The hypocrites began to whisper that in love of Ali the Holy Prophet had gone astray. On this occasion these verses were revealed. The Holy Prophet is mentioned as sahib (companion) because he was living among the people addressed in this verse.
"He does not speak of his own will" has also been mentioned in Deuteronomy 18: 18:
"Then the Lord said to me (Musa): "I will raise up for them a prophet like you, one of their own race, and I will put my words into his mouth. He shall convey all my commands to them."
It is also mentioned in John 16: 18:
(Isa said): "However, when he comes who is the spirit of truth, he will guide you into all the truth; for he will not speak on his own authority, but will tell only what he hears; and he will make known to you the things that are coming."
- 1. Ali/Pooya Commentary (53:1); for the full commentary, see Appendix K.