Vehāyasa = vihāyasa

i.e. air, sky; only used in acc. vehāyasaṃ in function of a loc. (cp. Vv-a.182: vehāyasaṃ = vehāyasa-bhūte hatthi-piṭṭhe), combined with ṭhita (standing in the air) Vv.41; Mhvs.1, Mhvs.24; Pv-a.14.