Mantras refer to a specific sounds, or phrases, which can be chanted or sung. But in case of Sun Salutation(Surya Namaskar), they are sung in praise of the Sun. You will get the benefits of suryanamaskar when you will use mantra. There are 12 mantras which praise different qualities of Sun and add a ocean spiritual touch to the entire practice.
We do Prostration to him who is affectionate to all.
We do prostration to him who is the cause for change.
We do prostration to him who induces activity.
We do prostration to him who diffuses light.
We do prostration to him who moves in the sky.
We do prostration to him nourishes all.
We do prostration to him who contains everything.
We do prostration to him who posseses rays.
We do prostration to him who is god of gods.
We do prostration to him who produces everything.
We do prostration to him who is fit to be worshipped.
We do prostration to him who is the cause of lustre.
There is only rule to remember during suryanamaskar is to chant them with gratefulness. Each suryanamaskar mantra has a specific meaning, but it is not important to know the meaning what each mantra means.
For those who want to understand Suryanamaskar mantras in layman language :
Om Mitraya namah (The friend of all)
Om Ravaye namah (Praised by all)
Om Suryaya namah (The guide of all)
Om Bhanave namah (The bestower of beauty)
Om Khagaya namah (Stimulator of the senses)
Om Pushne namah (The nourisher of all)
Om Hiranyagarbhaya namah (The creator)
Om Marichaye namah (Destroyer of disease)
Om Adityaya namah (The inspirer)
Om Savitre namah (The purifier)
Om Arkaya namah (The radiant)
Om Bhaskaraya namah (The illuminator)
Surya Namaskar Mantra Video│ Sun Salutation Mantra with Video