1 Samuel 18:8
And Saul was very wroth, and the saying displeased him; and he said, They have ascribed unto David ten thousands, and to me they have ascribed but thousands: and what can he have more but the kingdom? And Saul was very wroth, and the saying displeased him; and he said, They have ascribed unto David ten thousands, and to me they have ascribed but thousands: and what can he have more but the kingdom?
After Goliath was killed David remained with Saul, was entrusted with important responsibilities, and by modesty won affection in the royal household and among the people. The people's song and praise provoked Saul because it credited David with greater victories than himself, honoring David above him and crossing his will. He reacted to the saying with anger, jealousy, and displeasure.
His fury broke out in words and deeds that dishonored himself and dishonored God still more. He read the song as a threat to his rule and feared David would gain the people's favor and take the kingdom and his place as ruler. The response exposes his desire for praise and position. It shows weakness and contradiction in his character, with strength and gifted talent joined to a jealous and overbearing spirit.
In him good and evil were in collision with evil striving for supremacy, making him unjust and cruel toward his best friend. At times he could be tender and full of sympathy and be moved by sacred vocal music to impassioned devotion, praise, and prayer, but it was a wild and inordinate excitement that spent itself day and night until reaction and exhaustion came, and then his old disposition returned. He failed to trust that God could carry out His purposes for Israel without human opposition. Instead of humbly thanking God for Israel's deliverance, he gave way to jealousy and began to hate David.