Garudapurana 3.23.23

3.23.23

tīrthāṭanaṃ pādacairaiḥ kṛtaṃ cetpūrṇaṃ phalaṃ prāhurāryāḥ khagendra /
pādatrāṇaṃ pādarakṣāṃ ca kṛtvā tīrthāṭanaṃ pādahīnaṃ tadāhuḥ //

if the pilgrimage is undertaken on foot, the noble call the fruit complete, O King of Birds; / having put on footwear and foot protection, they say the pilgrimage is lacking one fourth [of its fruit].