In the following line, Wordsworth has used personification. In fact, this line shows us that there is something in this poem, which will make the heart of speaker leap up, probably joy. No doubt, in your daily speech you commonly say, “my heart leapt.” However, here just look at its expression, does heart have legs to leap up on its own? Of course not. Thus, we can say the poet has personified heart and given it characteristics of living beings.
Which Literary Device is used in the line, My heart leaps up when I behold?