الْأَوَّلُ: النِّيَّةُ ... وَوَقْتُهَا عِنْدَ ضَرْبِ يَدِهِ عَلَى مَا يَتَيَمَّمُ بِهِ
The intention must be present when the hand strikes the material used for Tayammum, or when the relevant wiping begins with dust already on the body. For Tayammum that will permit prayer, the text requires an intention of purification, permission for prayer, or another independent worship that itself requires purity.
Opening interactive controls...
Tayammum: The Eight Conditions of Validity and Valid Excuses
الْأَوَّلُ: النِّيَّةُ ... وَوَقْتُهَا عِنْدَ ضَرْبِ يَدِهِ عَلَى مَا يَتَيَمَّمُ بِهِ
The intention must be present when the hand strikes the material used for Tayammum, or when the relevant wiping begins with dust already on the body. For Tayammum that will permit prayer, the text requires an intention of purification, permission for prayer, or another independent worship that itself requires purity.