And He spoke many things to them in parables [i.e., brief stories to illustrate His teaching], saying, "Once a farmer went out [to his field] to plant grain.

He taught the people many things using parables [to illustrate His lessons]. In His teaching He said to them,

Fell

And those people [represented by the seed falling] along side of the road are those who have heard the word [of God], but the devil comes and takes away the word from their heart, so that they do not believe it and receive salvation.

So [then], we [Christians] should pay closer attention to the things we have heard, so that we do not drift away from [believing and practicing] them.

For if anyone is [only] a listener to the word and does not practice it, he is like a person who sees his natural face in a mirror,

It

"You people are [like] salt on the earth. But if salt loses its flavoring ability, how will it ever get it back again? From then on it would be good for nothing except to be thrown out onto the roadway and walked on by people. [Note: This was mined salt which, when losing its "saltiness" due to exposure to the sun or rain, was simply disposed of by being dumped onto the roadway where people walked].

General references

and it happened, as he sowed [i.e., scattering the seed by hand], some of it fell by the side of the road and birds came and ate it.