Lak al-waylāt takes the form of an imprecation, but in conversation it conveys alarm, irritation, or strong protest. Its literal sense is “may misfortunes be yours”; such expressions need not always function as a deliberate curse.
In innaka murjilī, inna marks emphasis, -ka is its subject pronoun, and murjilī conveys its predicate. Murjil is associated with the causative verb arjala, “to make someone walk,” while the final suffix points to the speaker.
The short utterance combines action, emotion, and cause: the added passenger may overwhelm the mount and make travel difficult for her.