satya parAkramam

When the sage Vishvamitra requested Dasaratha to send Rama with him to protect his yaga, he said "aham vedmi mahAtmAnam rAmam satya parAkramam". What did he mean when he said "satya parAkramam"?

Rama did not kill Ravana immediately when he was defeated and stood powerless. Instead He tried to see if he would change his mind and seek His favor; and killed him only when he came back in oppostion. Purvacharyas have said that this is the quality that is described by the phrase "satya parAkramam".

Unchanged

The question of Valimiki "ka: vIryavAn?" can also be explained in another way. When the Lord is called "bhagavAn", six qualities are described within: "gyAnam, shakti, balam, aishvaryam, vIryam and tejas". In this, what does vIryam mean? Bhattar defines it as, just as kastUri changes everyone's mind while itself remaining unchanged, it's the quality of the Lord to change everything while Himself remaining unchanged.

This quality is well seen with Rama. After leaving Rama at the banks of Ganga, Sumanthra returned to Ayodhya and told Dasaratha "vishaye te mahArAja! rAma vyasana karshitA:, api vrukshA: parimlAna: sapushpAnkura korakA:". That is, "O! King. Unable to bear separation from Rama, even the trees in your kingdom with their flowers, leaves and buds have withered". He continued to say that the water in pools and lakes had become hot and that the leaves in gardens and groves had dried up. Kooraththazhvan too describes the same in his Atimanushastavam.

Thus, while He remained unaffected, Rama changed both chetana and achetana beings. Therefore, one can also say that it is this quality that Valmiki had in mind when he asked the question "ka: vIryavAn?".