Sayyidah Aishah Siddiqah (may Allah be pleased with her) narrates from the Prophet (peace and blessings be upon him) concerning dry ablution (tayammum): "There are two strikes: one strike for the face and one strike for both arms up to the elbows."
Al-Bazzar recorded it; its chain contains al-Harish bin al-Khirrit, whom Abu Hatim, Abu Zur'ah and Imam al-Bukhari (may Allah have mercy on him) declared "da'if" (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الطهارة / 1418