All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
Allah, The Exalted, says (what means): {And We have certainly beautified the nearest heaven with lamps (stars) and have made (from) them what is thrown at the devils and have prepared for them the punishment of the Blaze.} [Quran 67:5]
The pronoun in the Arabic word Ja‘alnaaha in the verse refers to the lamps (stars). It is known to Arabic linguists that it is preferable to use a singular feminine pronoun to refer to the plural nouns of inanimate objects. Ash-Shirbeeni wrote, “The pronoun in Ja‘alnaaha refers to the lamps (stars).” [As-Siraaj Al-Muneer fi Al-I‘aanah ‘ala Ma‘rifat ba‘dh Ma‘aani Kalaam Rabbina Al-Hakeem Al-Khabeer 3/371]
Abu Hayyaan wrote:
“Allah, The Exalted, says (what means): {They ask you (O Muhammad) about the new moons. Say, "They are measurements of time for the people and for Hajj." And it is not righteousness to enter houses from the back, but righteousness is (in) one who fears Allah. And enter houses from their doors. And fear Allah that you may succeed.} [Quran 2:189] The pronoun in the (Arabic) word Abwaabiha (أبوابها - their doors) refers to the houses. A singular feminine pronoun (ها) is used in this context because the (Arabic) word Buyoot (houses) is a broken plural (irregular plural form of a noun). Regarding the plural form of inanimate feminine nouns, a distinction is made between a small number and a large number. It is more eloquent to use a plural pronoun if used to refer to a small number and to use a singular female pronoun if used to refer to a large number ... and the opposite is also permissible.” [Al-Bahr Al-Muheet fi At-Tafseer 2/239]
Allah knows best.