it was posted in the original post. 'Perhaps their punishment will be lightened through it as long as the branches do not dry up.' how is this not a dua?it is true the sentence does not invoke Allah (SWT) directly by saying Allahumma or any similar phrase but you can see the intention of the Prophet clearly that the punishment be lightened because of his action of placing the branches and 'hoping' Allah (SWT) will lessen the punishment till the branches dry up. this 'hope' is dua.