Al-Israa 17:105

With the truth We have sent down this [Qur’an] and with the truth it has descended[84], and We have not sent you [O Prophet] except as a bearer of glad tidings and a warner.

[84] It is repeated twice in the face of the ardent denial of the pagans of Makkah and their demand to provide them with miracles, asserting here that the Qur’an is a revelation from Allah: it contains truthful news and just rulings, as it is sent down by Gabriel (عليه السلام), the strong and trustworthy, to Prophet Muhammad (ﷺ), safeguarded against the devils, free from alteration, additions or omission, throughout all times.

And with the truth We have sent it [i.e., the Qur’ān] down, and with the truth it has descended. And We have not sent you, [O Muḥammad], except as a bringer of good tidings and a warner.

105. And with truth We have sent it down (i.e. the Qur’ân), and with truth it has descended. And We have sent you (O Muhammad صلى الله عليه و سلم) as nothing but a bearer of glad tidings (of Paradise for those who follow your Message of Islâmic Monotheism), and a warner (of Hell-fire for those who refuse to follow your Message of Islâmic Monotheism)[16].

[16] (V.17:105)
a) See the footnote of (V.3:85).
b) See the footnote of (V.4:80).

With truth have We sent it down, and with truth hath it descended. And We have sent thee as naught else save a bearer of good tidings and a warner.