20. Those to whom We have given the Scripture (Jews and Christians) recognize him (i.e. Muhammad صلى الله عليه وسلم as a Messenger of Allâh, and they also know that there is no Ilâh (God) but Allâh and Islâm is Allâh’s Religion), as they recognize their own sons. Those who have lost (destroyed) themselves will not believe.[1] (Tafsir At-Tabarî).
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(V.6:20) See the footnote of (V.3:85).