Tafsir of An-Najm 53:18

Indeed he saw of the greatest signs of his Lord. is similar to another Ayah,

لنريه من ءايتنا

In order that We might show him of Our Ayat. (17:1), meaning, signs that testify to Allah's might and greatness. Relying on these two Ayat, some scholars of Ahl us-Sunnah said that the Prophet did not see Allah during the Isra' journey, because Allah said,

لقد رأى من آيات ربه الكبرى

(Indeed he saw of the greatest signs of his Lord). They said that, had the Prophet seen his Lord, Allah would have conveyed this news and the Prophet would have narrated it to the people