Think not the king did banish thee, But thou the king. (1.3.10)
Foreshadowing alert! Gaunt's advice to Henry Bolingbroke as he's about to be banished (that he "pretend" he is the one in power) foreshadows the real events in the play. Bolingbroke ends up taking the mental exercise his father recommends quite literally by banishing (and later killing) the king.
Well, he is gone, and with him go these thoughts. (1.4.1)
In a fabulously mistaken moment, Green reassures the king that banishment will take care of the problem of Henry Bolingbroke, whose popularity in the kingdom had started to become worrying. This is, like pretty much everything Richard does, a passive and ineffective solution. While technically Green is right – getting rid of Henry helped the king feel better – this kind of thinking gave Henry all the time he needed to gather momentum and ended up costing Richard his kingdom.
Then England's ground, farewell! Sweet soil, adieu – My mother and my nurse that bears me yet! (1.3.15)
England's soil is an important symbol in the play. Richard's leasing of the land is used as evidence of his mistreatment of it. And by casting England as his mother, Henry Bolingbroke equates his sadness at leaving his father with his sadness at leaving his country.