At first blush, it looks like there are two heterogeneous themes that are intertwined (1. What happens with the seed? 2. Why parables?). But these two themes are closely related. The first describes a negative result (the seed perishes) and a positive (the seed sprouts). At the same time, speaking in parables seems to describe a situation that is partly negative (people don’t understand) and partly positive (people understand the mystery of the kingdom). We find that division both in the parable (4:4-7 and 4:8) and in the explanation (4:14-19 and 4:20) and also in the first recapitulation (4:11b-12 and 4:11a) and in the second (4:25b and 4:25a). We can observe the coherence also in another, less formal, point: Jesus begins to speak in parables because there is something missing in what the crowd sees and hears (4:11b-12; 4:24a), although the parable of the sower in particular is focused entirely on the importance of hearing correctly (4:3a, 9; 4:20). The cross connection becomes very clear when the recapitulation of the parable (“He who has ears to hear, let him hear) also forms the essence of the last general observation (4:23).1
1 Jésus se mit de nouveau à enseigner au bord de la mer. Une grande foule s'étant assemblée auprès de lui, il monta et s'assit dans une barque, sur la mer. Toute la foule était à terre sur le rivage.