إِنَّ رَبَّكَ هُوَ أَعْلَمُ مَن يَضِلُّ عَن سَبِيلِهِۦ ۖ وَهُوَ أَعْلَمُ بِٱلْمُهْتَدِينَ
Inna rabbaka huwa aAAlamu man ya d illu AAan sabeelihi wahuwa aAAlamu bi a lmuhtadeen a Verily, thy Sustainer knows best as to who strays from His path, and best knows He as to who are the right-guided.
 - Mohammad Asad
In fact, your Rabb knows best those people who have strayed from His Way and He knows best those who are on the Right Way.
 - Muhammad Farooq-i-Azam Malik
Indeed, your Lord knows best who has strayed from His Way and who is 'rightly' guided.
 - Mustafa Khattab
Lo! thy Lord, He knoweth best who erreth from His way; and He knoweth best (who are) the rightly guided.
 - Marmaduke Pickthall
Thy Lord knoweth best who strayeth from His Way. He knoweth best who they are that receive His guidance.
 - Abdullah Yusuf Ali