Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates that the Prophet (peace and blessings be upon him) said: "Were it not that I feared putting my Ummah to hardship, I would have commanded them to use the miswak at the time of every prayer."
Al-Tabarani recorded it in al-Mu'jam al-Kabir and al-Mu'jam al-Awsat; its chain contains a narrator, Sa'id bin Rashid, who is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 2551