Moffatt(i)
13 Those 'on the rock' are people who on hearing the word welcome it with enthusiasm, but they have no root; they believe for a while and fall away in the hour of trial.
14 As for the seed that fell among thorns, that means people who hear but who go and get choked with worries and money and the pleasures of life, so that they never ripen.
15 As for the seed in the good soil, that means those who hear and hold fast the word in a good and sound heart and so bear fruit stedfastly.