His son's name is "plowing wasteland", which coincides with the last sentence "plowing the desert yellow sand of the motherland into a beautiful garden"! You can say it's revolutionary optimism of martyrs, but I still think it's encouraging my son to follow in his father's footsteps.
And this is a will, equivalent to a poem. Its theme is self-evident, and it is passed on to my son, hoping that his son will continue to fight against the enemy and defend the motherland.