Surah 4. An-Nisaa', Ayah 55

I.e., in Abraham - implying that they are faithful to his message. It is to be borne in mind that the Prophet Muhammad, too, was a direct-line descendant of Abraham, whose message is confirmed and continued in the Qur'an.

 i.e., Abraham (ﷺ) or Muḥammad (ﷺ).

Cf. iv. 97, viii. 37, ix. 95, ixx. 68.