Maula Ali RadiAllahu Ta'la Anhu blew on an empty palm and...

Once a beggar approached the unbelievers and asked for something. The unbelievers sent the beggar to Sayyiduna Ali RadiAllahu Ta'la Anhu just for fun, who was sitting nearby. The beggar approached Sayyiduna Ali RadiAllahu Ta'la Anhu and begged him for something. Sayyiduna Ali RadiAllahu Ta'la Anhu recited Salat- Alan -Nabi ﷺ ten times and blew on the beggar's palm. Then, advising the beggar to close his fist and open it in front of the unbelievers, he RadiAllahu Ta'la Anhu sent him back to them. (The unbelievers were laughing expecting nothing to happen by just blowing on the palm). When the beggar opened his fist before them, there was a dinar in his palm! Having seen this miracle, several unbelievers embraced Islam. (Rahat-ul-Qulub, pp. 142)