Musar su Salmi 134:2

Therefore let a person ensure that his hands are clean of theft, fraud and infringement, and that his heart is pure through always dealing in good faith. And let him pray with concentration, according to his level of understanding. Then the words of his mouth and the meditations of his heart will be acceptable, as it is written, “Lift up your hands in holiness and bless Hashem!” (Tehillim 134:2). Amein.

From here one can infer the enormity of the punishment that awaits those who raise their hands while swearing vain oaths. According to an oral tradition that has come down to me, whoever raises his hands and fingers unnecessarily and other than in prayer will surely suffer some penalty for it shortly thereafter. And if this does not come to pass he should be even more concerned, for it undoubtedly means that the Heavenly court is allowing his guilt to accumulate until his measure is completely filled! Therefore, anyone who has become habituated in this sin should erect a protective fence for himself by uttering this verse before praying or reciting the blessing over the washing of the hands: “Lift up your hands to the Sanctuary and bless Hashem!” (Tehillim 134:2). This will give the Holy One Blessed is He pleasure, on account of which He will undoubtedly bestow upon him blessings and goodly gifts. However, this will only be true if his hands are free of robbery and theft. But if his hands are not free of robbery, theft and infringement, then of what significance is the lifting of his hands and fingers? On the contrary, it simply causes his iniquity to be brought to mind, thereby transforming the attribute of mercy into strict judgment.