I would like to know which sahaba did
Wa alaikum assalaam wa rahmatu Allahi wa barakatuh.
We are slightly confused by the question, because there is no surah named zamil, but aayah 9 of surah Az-Zumar (surah 39) is the aayah in the second part of your question, and may be the surah in question in the first part of the question. All aayaat were revealed to the Prophet Muhammed, , but there are some aayaat that had a reason for revelation, meaning a specific occurrence caused the timing of the revelation of an aayah, or it is known from a hadeeth that it was about a certain person.
The translation of the explanation of the meaning of aayah 9 of surah Az-Zumar is: Is one who worships devoutly during the hour of the night prostrating himself or standing (in adoration), who takes heed of the Hereafter, and who places his hope in the Mercy of his Lord - (like one who does not)? Say: "Are those equal, those who know and those who do not know? It is those who are endued with understanding that receive admonition.
Aayah 9 of surah Az-Zumar according to a tradition related by Ibn Abee Haatim was describing ‘Uthman bin Affaan, may Allah be pleased with him because of his plentiful night prayers and recitation of the Qur’an, but there are other traditions who name other companions as the one being described. Even if there are traditions that it describes a certain companion, it can apply to many Muslims past and present who spend a great portion of the night in prayer seeking the mercy of Allah and taking heed of the Hereafter.
You are welcome.