citraketuḥ - King Citraketu; tu - indeed; tām - that; vidyām - transcendental knowledge; yathā - just as; nārada-bhāṣitām - instructed by the great sage Nārada; dhārayām āsa - chanted; sapta-aham - continuously for one week; ap-bhakṣaḥ - only drinking water; su-samāhitaḥ - with great attention and care.

Fasting and drinking only water, Citraketu for one week continuously chanted with great care and attention the mantra given by Nārada Muni.