No article is used before a noun used in phrases as: to leave home, to send word, to caught fire, etc etc. Examples: He sent me word to see him. He left home. Here is my question: why not these phrases take articles like 1. He sent me a/the word to see him. 2. He left a/the home.
There is a very old distinction in English between a "house" (the building) and "home," which has a deeper significance. When you say "I'm going home" everyone knows what you mean; you don't need to indicate that you are talking about a specific home, because it is understood that you mean your own home. There are a handful of other words (church, work, school, bed) that don't require an article unless you need to refer to a specific location (such as, "the cat is on the bed" vs. "I'm going to bed"). Being at home, attending church, being at work, or sleeping in your bed are thought of as life activities as much as they are actual places.
The word "word" in English has multiple meanings. In the phrase "send word" it means "tidings" or "information." When used in that sense, it is an uncountable noun.
According to the Oxford English Dictionary, up until the 1600s or so, people did say, "to catch a fire" but over time, "to catch fire" became an idiom and the article was dropped.
I don't know any rule by which to know which English words need articles and which don't. For example, "He sent me word to see him," could also be expressed, "He sent me a message to see him."
Why do we put an article before "message" but not before "word"? It's the way the language evolved.
Sometimes we say "It caught fire" and sometimes we say "It caught on fire."
Home: Place of Refuge
When we say "the home," we often mean an institution such as a nursing home. When we mean at home where we live, we just say "home." The same applies for "shelter."
We say: They found shelter under the overhang from the heavy rain.
But when the rain stops, we say:
When the storm was over, they left the shelter of the overhang.
Note that we use the article in this sentence. "Refuge" is used the same way:
They found refuge... They left their refuge...
It's as though the human wants no separation between self and words that mean help in time of need like shelter, refuge, and home. Note that there are no articles before "help," "time," and "need." All these words are basic, intimate human instinct.
Likewise, when something catches fire there is no time to waste with articles. Either we must flee for our lives or we must quickly add heavier fuel to the kindling to build the fire for cooking. And one's word is all a person has; sending one's word is as good as sending oneself. If one's word is no good, the self is no good.
To send a message indicates that the person has status, perhaps of noble birth.
These hypotheses are based on medieval English culture out of which today's English language evolved. I cannot say for sure that this rule holds but it appears to apply in some cases.