Revākhaṇḍa ascribed to the Vāyupurāṇa (RKV) 97.160

97.160

īdṛśānvarjayecchrāddhe dāne sarvavrateṣu ca /
gāyatrīsāramātro 'pi varaṃ vipraḥ suyantritaḥ //

such men one must avoid in ancestral rites, gifts, and all observances. / A well-restrained brāhmaṇa, even if he knows only the essence of the Gāyatrī, is preferable;