When my brothers and I were children, my grandmother would catch us in the act of stating "I hate _____". She wouldn't allow us the use of the "h" word, and would regularly be heard replying "you don't hate anything."
How many times a day do we say it?
Samma Vaca, or Right Speech, like the other branches of the Noble Eightfold Path, plays an important and supportive part in our meditation practice. What we think, we become. If we think about what we hate, we become hateful. When we speak out of a hateful state, we feed the hateful thinking, exacerbating the cycle.
If we're speaking about something we "hate", the mind is dwelling on something it doesn't like, which in turn gives rise to an unpleasant state of mind.
Who wants that?
If we truly aim to eradicate our hearts and minds of hate, we can't allow it any space. So as we move through our day, we can practice being mindful of how we speak by keeping an ear out for this one word. The practice of aiming to eliminate an unbeneficial word from our vocabulary can be very interesting and challenging, as it illuminates our habitual patterns of speaking, which point towards our habitual patterns of thinking.
As in meditation, when we are able to bring our awareness back after the mind has wandered, each time we catch ourselves about to speak, or just after speaking this unwelcome word, we strengthen our awareness and resolve.
Like this, over time, we gradually clean up our hearts and minds, leaving no space for hate.