رَسُولٌ مِّنَ ٱللَّهِ يَتْلُوا۟ صُحُفًا مُّطَهَّرَةً
Rasoolum minal laahi yatlu suhufam mutahharah
a messenger from God, reciting purified scriptures,
The clear evidence promised one line earlier turns out to be a person — a messenger, reciting. Surah al-Bayyina takes its name from that word, and the proof it offers is someone who arrives and speaks. Suhuf is the plain word for leaves of writing, used at 87:19 for the writings of Ibrahim and Musa, which describes this revelation to People of the Book in vocabulary already theirs.