The Holy Quran is the sacred word of the Lord Almighty Allah (Subhanahu Wa Ta'ala) and is at the peak of excellence. It is the zenith of all eloquence. Each verse of it is an ocean of knowledge and divine secrets.
The usual meaning of the word, "Yateem" as orphan is correct. However, that is not the only meaning of this word. The exegetes (Mufassirin) have described many other meanings of this word.
Imam Mujahid (May Allah be well pleased with him), who gained especial knowledge and Ma'arifah from the Holy Prophet (Sallallahu alaihi wa sallam) through Hadhrat Abdullah Bin Abbas (May Allah be well pleased with him) and other Sahabah. He is a great Tabi'e, an erudite scholar and a Muhaddith. He says:
Translation: The word "Yateem" is derived from "Durre Yateem," which means the rare pearl, which has no equal in value. (Tafseer Qurtubi, Tafseer Tha'alabi, Surah Dhuha)
In light of this, the meaning of verse would be:
O Beloved Prophet! Did He not find you peerless in greatness that there is no one of your status, then He kept you in the shade of His benevolence.
‘Allama Syed Muhammad Alusi Baghdadi (May Allah shower His mercy on him) has written this meaning in Tafseer Ruh Al Ma'ani and has declared this meaning only as the better and worthier one.
He writes:
Translation: It is better that this verse be interpreted that, "Did He not find you peerless in the universe that this universe has not seen any pearl more lustrous than you, so He kept you in the shade of His benevolence and chose you for His especial proximity and love.
In Ruh Al Bayan, on the authority of the author of Kasshaf, Allama Ismail Haqqi (May Allah shower His mercy on him), has declared this meaning of this verse as incomparable.
Thus, the said meaning of the word "Yateem" is correct, as has been made clear through the explanations of the Imams of Tafseer. This is also supported by the Hadith. Hadhrat Ali (May Allah be well pleased with him) said, while describing the matchless personality of the Holy Prophet (Sallallahu alaihi wa sallam):
Translation: Anyone who praises and extols the Holy Prophet (Sallallahu alaihi wa sallam) inevitably ends up saying that I have not seen anyone like Him before Him or after. (Shamaail Tirmidhi, Pg. No. 1; Musnad Iman Ahmed bin Hambal, Vol. 1, Pg. No. 187, 188; Sahih Ibn Hibban, Vol. 6, Pg. No. 58).