This Hadith includes the words:
إِنَّمَا الأَعْمَالُ بِالنِّيَّاتِ (Sahih al-Bukhari: 1)
Translation: Actions are judged by intentions.
Matn (متن) is the wording that comes after the sanad. It contains what the Hadith reports.
• The words about intentions above are part of this Hadith's matn.
• Umar hearing and transmitting it concerns its sanad.
• A matn need not be a saying: it can also report an action or a quality.