Just by words this entire Universe came into existence, in Vedic days via Vedic hymns in havanas many divine souls took birth, Mata Draupadi/Drupad appeared from fire sacrifice via vedic hymn, Pandavas appeared by vedic mantra chanted by mata Kunti, etc. However pronunciation of vedic verse in an improper way gave birth to many demons, bad omens etc. Muni Agatsya, rishi durwasa gave birth to a fire demon Kritiya by the help of Vedic verse in the mode of ignorance.
How are words, images etc captured?
--Same like we see how images, music, videos are transferred Via Wi-Fi, Bluetooth, messages, emails, MMS, etc from one phone/PC to another, now these words, pictures are visible in the air but can only be seen after we get it on our device.
--When we tune our Radio we are actually catching those words which are already present within this Cosmology, via the help of meeting of 2 frequencies we can hear it on our device, those words were already present but we need a device to hear them. Yogi use to tune themselves with the frequency of nature, cosmology, animals, birds etc & use to understand them.
Sri Krishna spoke Gita to Arjuna which was not been written by anybody at the same moment but later, Sri Vedvyasji tuned his sound chakra the Vishudhi & captured those words of Sri Krishna present within the cosmo, he orally dictated & Lord Ganesha made a note of it which were The 18 Purans, Eithas like Mahabharata, etc.
Use of slang is common now-a-days, use of slang produces bad omens/demons & it returns in a Sin or curse form to attack us in future, it can be linked with karmic cycle which leads to our sorrows, ignored by others, or any sorts of suffering.
Similarly Good words, when we say/chant the holy name of Sri Ram, Krishna, Mahadev etc. They actually appear in their form & boon to the one who said & all those who heard thy holy name. So the rishis said think trice before we speak else remain silent.