It is narrated from Nafi' (may Allah have mercy on him) that whenever Sayyiduna Ibn Umar (may Allah be pleased with them both) performed ablution, he would rub and wash his cheeks; sometimes he would run his fingers through his beard, and sometimes he would leave it.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 251