I say, and with God's success: His wiping is invalidated; because it is not permissible to combine washing and wiping, so his wiping is invalidated. Then it is considered: if he is not in a state of ritual impurity, he is not required to perform ablution, and it suffices him to wash his feet only, without washing the rest of the limbs. However, if he is in a state of ritual impurity, he must perform ablution; because the contact of water with the foot is not a nullifier in reality, but the nullifier is the previous state of impurity. However, when his foot became wet, the effect of the impurity appeared on the foot. Refer to: 'Umdah al-Ri'ayah 1: 114, and Sharh al-Wiqayah p. 114, and God knows best.