The seed is the Word of God.

“And when a great multitude had gathered, and they had come to Him from every city, He spoke by a parable: “A sower went out to sow his seed. And as he sowed, some fell by the wayside; and it was trampled down, and the birds of the air devoured it. Some fell on rock; and as soon as it sprang up, it withered away because it lacked moisture. And some fell among thorns, and the thorns sprang up with it and choked it. But others fell on good ground, sprang up, and yielded a crop a hundredfold.” When He had said these things He cried, “He who has ears to hear, let him hear!” Then His disciples asked Him, saying, “What does this parable mean?” And He said, “To you it has been given to know the mysteries of the kingdom of God, but to the rest it is given in parables, that ‘Seeing they may not see, And hearing they may not understand.’ “Now the parable is this: The seed is the word of God. Those by the wayside are the ones who hear; then the devil comes and takes away the word out of their hearts, lest they should believe and be saved. But the ones on the rock are those who, when they hear, receive the word with joy; and these have no root, who believe for a while and in time of temptation fall away. Now the ones that fell among thorns are those who, when they have heard, go out and are choked with cares, riches, and pleasures of life, and bring no fruit to maturity. But the ones that fell on the good ground are those who, having heard the word with a noble and good heart, keep it and bear fruit with patience.”
‭‭Luke‬ ‭8‬:‭4‬-‭15‬ ‭NKJV‬‬