Through his light, the traps laid by the evil spirits, who are active at night, are revealed.

In later times, apparently through Assyrian influence, the reckoning of time was altered to the extent of making the day begin with sunrise, instead of with the approach of night; and this, together with the accommodation of the lunar cycle to the movements of the sun, brought about a partial change of the former conditions, and gave somewhat greater prominence to Shamash.

As a consequence, the role of Sin is not as prominent in the hymns that belong to a later period as in those of earlier days.
The oracles of the Assyrian kings are addressed to Shamash, and not to Sin.

Moreover, the personal factor in the case of Sin, if one may express oneself thus, is not as strong as in that of some other gods.
His traits are of a more general kind.

He is supreme; there is none like him, and the spirits are subservient to his will.