So if you are in doubt, [O Muhammad], about that which We (10:94)

﴿فَإِن كُنتَ فِي شَكٍّ مِّمَّا أَنزَلْنَا إِلَيْكَ فَاسْأَلِ الَّذِينَ يَقْرَءُونَ الْكِتَابَ مِن قَبْلِكَ ۚ لَقَدْ جَاءَكَ الْحَقُّ مِن رَّبِّكَ فَلَا تَكُونَنَّ مِنَ الْمُمْتَرِينَ﴾
[ يونس: 94]

10:94 So if you are in doubt, [O Muhammad], about that which We have revealed to you, then ask those who have been reading the Scripture before you. The truth has certainly come to you from your Lord, so never be among the doubters.

If you, O Messenger, are in doubt or confusion about the reality of the Qur’ān that I have revealed to you, then ask those Jews who read the Torah and the Christians who read the Gospel to confirm it.
They will tell you that what was revealed to you is the truth because they have the description of it in their scriptures.
The truth, about which there is no doubt, has come to you from your Lord, so do not be of those who have doubt.

So if you (O Muhammad SAW) are in doubt concerning that which We have revealed unto you, [i.e. that your name is written in the Taurat (Torah) and the Injeel (Gospel)] then ask those who are reading the Book [the Taurat (Torah) and the Injeel (Gospel)] before you. Verily, the truth has come to you from your Lord. So be not of those who doubt (it).

phonetic Transliteration

Fain kunta fee shakkin mimma anzalnna ilayka faisali allatheena yaqraoona alkitaba min qablika laqad jaaka alhaqqu min rabbika fala takoonanna mina almumtareena

Abdullah Yusuf Ali - Translation

If thou wert in doubt as to what We have revealed unto thee, then ask those who have been reading the Book from before thee: the Truth hath indeed come to thee from thy Lord: so be in no wise of those in doubt.

Safi-ur-Rahman al-Mubarakpuri

So if you are in doubt concerning that which We have revealed unto you, then ask those who are reading the Book before you. Verily, the truth has come to you from your Lord. So be not of those who doubt (it).

Page 219 English transliteration