Taaloot (Saul) was a good man whom Allaah praised in the Quran
16-12-2015 | IslamWeb
Question:
Dawood’s (peace be upon him) relation with Taloot: As per his promise, Taloot married his daughter to Dawood and appointed him the commander of his army. Gradually, the discussion of Dawood’s greatness and excellence increased among the people. With these discussions, love and affection for him increased manifold in the hearts of the people. Meanwhile the friendship of Dawood with Yunasan (son of Taloot) grew stronger. This widespread fame and acceptance of Dawood among the people became a cause of jealousy and envy for Taloot. This fire of jealousy against Dawood began raging fiercely, until one day Taloot made a plan to kill him. Yunasan tried unsuccessfully to stop his father from this disgraceful act. Taloot sent Dawood to many dangerous wars so that he would be killed by the enemy. However, Dawood always emerged victorious. Talut devised another scheme to kill Dawood, but the latter got news of it. He left the place that same night along with his relatives and took shelter in a cave. Gradually, Dawood’s other relatives and the poor, weak and needy also took shelter along with him. Dawood along with the entire group sought refuge in the neighbouring kingdom of Palestine. When Talut learnt of this, he attacked the kingdom of Palestine but was defeated and the battle ended with his death. His soldiers fled the battlefield. The kingdom fell in the hands of the Dawood. During the same period, Shamueel (Samuel) (peace be upon him) passed away, and the prophethood transferred to Dawood. He fought several wars, and Allaah gave Him victory. Hence, he was successful in bringing many kingdoms within the realm of Bani Israel. How much of this narrative is correct? Was Taloot a good man?
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad 
is His slave and Messenger.
Taaloot (Saul) was a righteous man whom Allaah, The Exalted, praised and chose, as highlighted in the verse that reads (what means): {...He said: Indeed, Allaah has chosen him over you and has increased him abundantly in knowledge and stature...} [Quran 2:247]
It is unbecoming of such a righteous king whom Allaah praised to do what this narrative suggests as reported in the Israa'eeliyyaat (the body of narratives originating from Jewish and Christian traditions, rather than from other well-accepted sources that quote the Prophet ).
Al-Haafith Ibn Katheer 
cited a narrative similar to the one you referred to in the question and then commented, "This narrative was cited by Ibn Jareer in his history book on the authority of As-Suddi with its chain of narration. Some parts of the story may be inaccurate, and their authenticity is questionable." [Al-Bidaayah wan-Nihaayah]
Allaah knows best.