Meanings
From blow (“to cause to explode, shatter, or be utterly destroyed”) + to + kingdom come (“place that one will go to after one’s death, afterlife; death; state of complete annihilation; heaven or paradise”). Kingdom come is derived from the phrase “Thy kingdom come” from the Lord’s Prayer which is recorded in Matthew 6:9–13 and Luke 11:2–4 in the Bible:[1] see, for example, Matthew 6:10 in the King James Version (spelling modernized): “Thy kingdom come. Thy will be done, in earth, as it is in heaven.”[2] By these sentences, Jesus seeks the establishment of the rule of God the Father over the Earth in the future.
How to pronounce "blow to kingdom come":
To totally destroy (something); to annihilate or wipe out (something).