The full text of the message of the Leader of the Islamic Revolution is as follows: 

In the name of God, the Most Compassionate, the Most Merciful. 
The painful and disastrous mining incident in Golestan [province], which led to the death of a group of industrious and suffering workers and left some others of them trapped, deeply saddened and bereaved me. All possible measures must be adopted to rescue the ones trapped [in the mine]. The tragedy is immensely bitter and I hope for God's grace in this regard. I do extend my condolences to the families of the dear victims, pray for them patience and calm and ask for divine intervention to the relief of those trapped. Efforts by various organizations [involved in the rescue process] are appreciated. Those efforts they must step up to the utmost level. 

Seyyed Ali Khamenei 
May 4, 2017