Then God told Isaiah, "Go and meet Ahaz. Take your son Shear-jashub (A-Remnant-Will-Return) with you." Isaiah 7:3 (MSG)
Names have meaning. There can be historical meaning in a name (Just ask any "Doubting Thomas"). There can be linguistic meaning in a name (Thomas is derived from an ancient word meaning "twin," which was always a head-scratcher for me because I'm not a twin, but my brothers are). Names have literary meanings (Little Tommy Tucker, for example). Names give way to nick names (Tommy, T, TV, Tompt, and Tommer Toes are a few I've had through the years).
Our names are metaphors. Something which represents something else without using "like" or "as." The word "Tom" represents me. It's not "like" me. "Tom" is me. For better or worse, names become intensely personal metaphors to which all sorts of meaning can and will be attached in many different layers.
I find it fascinating that Isaiah chose to name his son Shear-jashub which means "A Remnant-Will-Return". The name of Isaiah's son was part of his prophecy. Isaiah's life-long message is of judgement and redemption, of doom and hope. He tells of Jerusalem's imminent fall and devastation, but also of God's eventual redemption and salvation. Today's chapter is a microcosm of his message. Doom is coming (in the form of Assyria's seige of Jerusalem) but also salvation (a virgin-born Messiah).
Part of Isaiah's message is that after the people are taken into captivity, eventually a remnant would return to Jerusalem (the prophecy was fulfilled and the story told in the book of Nehemiah). So, Isaiah names his son Shear-jashub and his son becomes, metaphorically, a part of Isaiah's message. Shear-jashub represented the future, and his name represented God's prophetic message. Isaiah's child became a living, breathing, walking representation of his life-long sermon.