Figurative language (expression) is when you use a word or phrase that does not carry its normal (literal) meaning.
For example, the eye of a needle is a figurative expression. It is a well-known fact that needles do not have eyes. Nonetheless, here the opening of a needle through which you pass the thread is figuratively described as an eye.
A gerund is a noun formed with a verb ending in ing. Words like swimming, tying, dreaming, eating, fishing, and drinking can all be used as gerunds.
A phrase is a group of words that does not have a subject and a verb. Phrases do not convey a complete thought on their own.
Now you know what gerund and phrase are, let's take a look at the gerund phrase. A gerund phrase always follows these rules:
Eating ice cream on a hot day is the subject of the verb 'can be'.