This is the 6337th most frequent Turkish word.
ışığına
"To its/her/his/their light."
In this sentence, 'ışığına' is used to refer to the light associated with the book, treated as a metaphorical or actual bright light coming from it.
Kitabın ışığına hayran kaldım.
I admired the light of the book.
Here, 'ışığına' indicates movement towards the light of the sun, emphasizing direction and association with 'Güneş' as the owner of the light.
Güneş ışığına doğru yürüdüm.
I walked towards the sunlight.
This usage of 'ışığına' connects the light to the lamp in the house, signifying possession or origin of the light.