"Believe in Allah and His words" (Qur'an 7:158). Al-Hasan said: meaning His revelation which was sent down upon Muhammad.
﴿يُؤمن بِاللَّه وكلماته﴾ قَالَ الْحَسَنُ: يَعْنِي: وَحْيَهُ الَّذِي أنزل على مُحَمَّد.