Is wiping one’s face after supplications acceptable? I was told that all the prophetic traditions that persuade it are weak and that doing so in an innovation?
Imam al-Tirmidhi relates the following prophetic tradition on behalf of ‘Umar the son of al-Khattab [Allah be pleased with him]: “If the Prophet [Allah's peace and blessings be upon him] raised his hands in supplication, he would not bring them down until he wiped his face.”Imam al-Tirmidhi commenting on this tradition wrote, “It is strange” meaning only one person narrated it.
There is another prophetic tradition related by Imam Abu Dawod from the son of ‘Abbas that alludes to the same meaning as well. However, Imam al-Nawwawi states “Everone of these hadith has a weakness in their chains.” al-Adhkar pg. 399.
At a quick glance it may seem that those who corrected you are on point. However, Ibn Hajar states, after mentioning the narration of ‘Umar above, “It was related by al-Tirmidhi and it has support from the narraration of Abi Dawud on behalf of Ibn ‘Abbas and others. All of these narration, when brought together, deem the status of tradition be raised to that of good [hassan]. Thus, although they are weak in isolation, when brought together they strengthen the status of the hadith.” [subul al-Salam vol. 4 pg. 219.
Thus, dear brother, there is nothing wrong with acting on the Hadith of ‘Umar and no one should censure your for doing so. However, keep in mind that you must instruct the people with kindess and mercy. Don’t take this answer and shove it in their faces. Be kind, gentle and patient.
Allah knows best