Ranganatha Ashtakam was composed by Adi Sankara Bhagavatpada when he stood before Lord Sri Ranganatha in Srirangam, which he visited during his travels. This Ashtakam (an octet) reveals that Adi Sankara was overwhelmed by Lord Ranganatha that his mind is instantly captivated and he revels in that feeling.
Adi Sankara Bhagavatpada sings in praise of Sri Ranganatha in 8 slokas, of which 7 of them end with the words ‘Ramathaam manomay’. He is immensely captivated by the Lord and he sings by bringing out all the attributes in every word. The devotee who sings this in the morning will fulfill his wishes and will attain the abode of Sri Ranganathaand also will take him in the path of liberation.