وَصَلَتْ رِسَالَتُكَ.
Your message has arrived.
If the listener does not know that the message arrived, the sentence conveys new information. If the listener already knows and the speaker wishes to display awareness of the fact, the intended effect may be lāzim fāʾidat al-khabar.
The words remain unchanged while their function varies with shared knowledge and discourse purpose. Displaying awareness is not necessarily pointless repetition.