Aśauca-vidhi (Rules of Impurity) within Śrāddha-kalpa — Chapter on Testing/Selecting Brahmanas and Honoring the Atithi
वानप्रस्थेन ऋषयो वालखिल्यैः पुरन्दरः / यतीनां तु कृता पूजा साक्षाद्ब्रह्मा तुं पूजितः
vānaprasthena ṛṣayo vālakhilyaiḥ purandaraḥ / yatīnāṃ tu kṛtā pūjā sākṣādbrahmā tuṃ pūjitaḥ
By honoring a vānaprastha, the ṛṣis are honored; by honoring the Vālakhilyas, Purandara (Indra) is honored; and by worshiping the yatis, Brahmā himself is worshiped directly.