وَالنِّيَّةُ فَرْضٌ فِي التَّيَمُّمِ، وَمُسْتَحَبَّةٌ فِي الْوُضُوءِ.
Meaning: Intention is obligatory for tayammum and recommended for wudu.
Tayammum requires a deliberate intention connected with purification or entitlement to worship. Accidentally touching dust does not become tayammum.