Wa alaykum salam wa rahmatuLlahi wa barakatuHu,

In his Sahih v. 4, p. 190, Imam Bukhari related on the authority of Jabir who said that the Prophet Muhammad (sallaAllahu alayhie wa sallam) would teach the Sahabah istikharah like he would teach a chapter from the Holy Qur’an. Whenever one needs guidance on an important matter he should perform the istikharah prayer [the prayer for guidance] by first performing two rak’ahs and then [i.e. after the two raka’at – units of prayer] reading this dua دعاء الاستخارة.

And Allah knows best.

Shafiifiqh.com Fatwa Dept.