(As the truth always consists in what your Lord wills and decrees,) so is this the truth from your Lord (in this matter); do not then be, (and you are never expected to be,) of those who doubt
This is the Truth from your Rabb, so do not be of those who doubt!
Sayyed Abbas Sadr-Ameli
(This about Jesus is) the truth from your Lord, therefore be not you of the doubters
Al-muntakhab fi tafsir al-Qur'an al-Karim
This is the absolute truth, declared in words by Allah, your Creator, therefore, do not let their intentional assertion of what is false make you doubtful and anxious