Bhagavatapurana 6.7.33

6.7.33

na garhayanti hy artheṣu yaviṣṭhāṅghryabhivādanam /
chandobhyo 'nyatra na brahman vayo jyaiṣṭhyasya kāraṇam //

33. In fact when there are high purposes to be served the wise do not object to (condemn) bowing to the feet of the younger; O brahmin, age is the cause of superiority in matters other than the Vedas (Vedic relations).