Salaam. In the Quran 3:159 “…then when you have taken a decision, tawakkal (put your trust )in Allah. Syed Qutb , says that the Rasul s.a.w. quotes this verse when the sahabah went to see him and ask whether he would want to reconsider the decision to protect Medina at Uhud . The lesson to be drawn is that once a decision has been taken, one should not entertain thoughts of reconsidering, etc. but rather act it out resolutely. In this case he will still uphold the decision to protect Medina at Uhud . a)Is the tradition relating to the quotation of the verse during this incident a sahih one? b)Could you inform me of other verses that stressed on the firmness & resoluteness of character and to avoid being indecisive?

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.

If you mean that the Prophet recited this verse as an evidence for his decision, then we have not come across anything which supports this meaning. However, if you mean that he acted according to the verse, then this is true, this is the interpretation given by Al-Bukhari about this verse, and other scholars .

As regards other verses which teach a Muslim to be decisive and resolute, then all the verses which are about putting one's trust in Allaah refer to this meaning, like the Saying of Allaah (which means): {And upon Allaah rely, if you should be believers.}[Quran 5:23]